This is a major refactor of the links subparser, previously known as anchors subparser.
Closes#355, #534
BREAKING CHANGE: `excludeTrailingPunctuationFromURLs` option was removed. This is now the default behavior
This feature was seen as a bit "duh!" since midword asterisks are not really a thing and, for these situations, you can simply escape the asterisk character.
Closes#499
BREAKING CHANGE: literalMidWordAsterisks option was removed and so asterisks will always retain their markdown magic meaning in a source text.
If you're using this feature, and you wish to retain this option, you can find a shim here: <https://gist.github.com/tivie/7f8a88c89ffb00d2afe6c59a25528386>
