* parser slowness with certain inputs ([da8fb53](https://github.com/showdownjs/showdown/commit/da8fb53)), closes [#315](https://github.com/showdownjs/showdown/issues/315)
### Features
* **requireSpaceBeforeHeadingText:** option to make space between `#` and header text mandatory ([5d19877](https://github.com/showdownjs/showdown/commit/5d19877)), closes [#277](https://github.com/showdownjs/showdown/issues/277)
* **lists:** lines with mutiple dashes being parsed as multilists ([10b3410](https://github.com/showdownjs/showdown/commit/10b3410)), closes [#312](https://github.com/showdownjs/showdown/issues/312)
* **nbsp:** nbsp are replaced with simple spaces ([6e90f7c](https://github.com/showdownjs/showdown/commit/6e90f7c))
* **simpleLineBreaks:** option that parses linebreaks as <br/>. This option enables linebreaks to always be treated as `<br />` tags
without needing to add spaces in front of the line, the same way GitHub does. ([0942b5e](https://github.com/showdownjs/showdown/commit/0942b5e)), closes [#206](https://github.com/showdownjs/showdown/issues/206)
* **excludeTrailingPunctuationFromURLs:** option that excludes trailing punctuation from auto linked URLs. ([d2fc2a0](https://github.com/showdownjs/showdown/commit/d2fc2a0)), closes [#266](https://github.com/showdownjs/showdown/issues/266) [#308](https://github.com/showdownjs/showdown/issues/308)
* **disableForced4SpacesIndentedSublists:** option that disables the requirement of indenting nested sublists by 4 spaces. The option is disabled by default ([0be39bc](https://github.com/showdownjs/showdown/commit/0be39bc))
### BREAKING CHANGES
* syntax for sublists is now more restrictive. Before, sublists SHOULD be
indented by 4 spaces, but indenting at least 2 spaces would work.
Now, sublists MUST be indented 4 spaces or they won't work.
With this input:
```md
* one
* two
* three
```
Before (ouput):
```html
<ul>
<li>one
<ul>
<li>two
<ul><li>three</li></ul>
<li>
</ul>
</li>
<ul>
```
After (output):
```html
<ul>
<li>one</li>
<li>two
<ul><li>three</li></ul>
</li>
</ul>
```
To migrate either fix source md files or activate the option `disableForced4SpacesIndentedSublists`:
* **bower:** fix sourceMappingURL errors in bower by including source ([9b5a233](https://github.com/showdownjs/showdown/commit/9b5a233)), closes [#200](https://github.com/showdownjs/showdown/issues/200)
* **comments:** Fix html comment parser ([238726c](https://github.com/showdownjs/showdown/commit/238726c)), closes [#276](https://github.com/showdownjs/showdown/issues/276)
* **tables:** add check for undefined on text due to failing to parse tables ([6e30a48](https://github.com/showdownjs/showdown/commit/6e30a48)), author [stewartmckee](https://github.com/stewartmckee), closes [#257](https://github.com/showdownjs/showdown/pull/247)
* **literalMidWordUnderscores:** fix different behavior with asterisks ([e86aea8](https://github.com/showdownjs/showdown/commit/e86aea8)), closes [#198](https://github.com/showdownjs/showdown/issues/198)
* **simpleautolink:** fix mail simpleAutoLink to ignore urls with @ symbol ([8ebb25e](https://github.com/showdownjs/showdown/commit/8ebb25e)), closes [#204](https://github.com/showdownjs/showdown/issues/204)
### Features
* **eventDispatcher:** add an event dispatcher to converter ([2734326](https://github.com/showdownjs/showdown/commit/2734326))
* **hashHTMLSpans:** add support for hashing span elements ([3097bd4](https://github.com/showdownjs/showdown/commit/3097bd4)), closes [#196](https://github.com/showdownjs/showdown/issues/196) [#175](https://github.com/showdownjs/showdown/issues/175)
* fix undefined error in malformed tables ([6176977](http://github.com/showdownjs/showdown/commit/6176977))
Cannot read property 'trim' of undefined happens when the parser is fed a malformed table.
This happens in live previews (for instance, when using Angularjs).
* add support for md span elements in table headers ([789dc18](http://github.com/showdownjs/showdown/commit/789dc18))
Closes #179
* **italicsAndBold:**
* fix broken em/strong tags when used with literalMidWordUnderscores ([7ee2017](http://github.com/showdownjs/showdown/commit/7ee2017))
When literalMidWordUnderscoresis set to true, em and strong tags that start or end a paragraph don't get parsed as such.
This fixes this issue.
Closes #174
* fix underscores not being correctly parsed when used in conjunction with literalMidWordsUnderscores option ([c9e85f1](http://github.com/showdownjs/showdown/commit/c9e85f1))
* **codeSpans:** Fix issue with code html tags not being correctly escaped ([5f043ca](http://github.com/showdownjs/showdown/commit/5f043ca))
* **images:** fix alt attribute not being escaped correctly ([542194e](http://github.com/showdownjs/showdown/commit/542194e))
* **headerLevelStart:** fix for NaN error when specifying a non number as headerLevelStart param ([be72b487](http://github.com/showdownjs/showdown/commit/be72b487))
* **headerLevelStart:** add support for setting the header starting level ([b84ac67d](http://github.com/showdownjs/showdown/commit/b84ac67d), closes [#69](http://github.com/showdownjs/showdown/issues/69))
* **image dimensions:** add support for setting image dimensions within markdown syntax ([af82c2b6](http://github.com/showdownjs/showdown/commit/af82c2b6), closes [#143](http://github.com/showdownjs/showdown/issues/143))
* **noHeaderId:** add option to suppress automatic generation of ids in headers ([7ac893e9](http://github.com/showdownjs/showdown/commit/7ac893e9))
* **showdown.getDefaultOptions:** add method to retrieve default global options keypairs ([2de53a7d](http://github.com/showdownjs/showdown/commit/2de53a7d))
* Deprecates `showdown.extensions` property. To migrate, extensions should use the new method `showdown.extension(<ext name>, <extension>)` to register.
For more information on the new extension loading mechanism, please check the wiki pages.
- add unique id prefix and suffix to headers ([c367a4b9](http://github.com/showdownjs/showdown/commit/c367a4b9), closes [#81](http://github.com/showdownjs/showdown/issues/81), [#82](http://github.com/showdownjs/showdown/issues/82))
* **options.omitExtraWLInCodeBlocks:** fix for options.omitExtraWLInCodeBlocks only applying in gitHub flavoured code b ([e6f40e19](http://github.com/showdownjs/showdown/commit/e6f40e19))
* **showdown:** fix for options merging into globalOptions ([ddd6011d](http://github.com/showdownjs/showdown/commit/ddd6011d), closes [#153](http://github.com/showdownjs/showdown/issues/153))
The system, however, is not final and will probably be changed until the final version([0fd10cb] (http://github.com/showdownjs/showdown/commit/0fd10cb))
* **allowBlockIndents:** indented inline block elements can now be parsed as markdown ([f6326b84](http://github.com/showdownjs/showdown/commit/f6326b84))
* **omitExtraWLInCodeBlocks:** add option to omit extra newline at the end of codeblocks ([141e3f5](http://github.com/showdownjs/showdown/commit/141e3f5))
* **prefixHeaderId:** add options to prefix header ids to prevent id clash ([141e3f5](http://github.com/showdownjs/showdown/commit/141e3f5))
* **extensions:** showdown extensions were removed from core package and now live in their own repository. See the [project's github page](https://github.com/showdownjs) for available extensions
