Issue #298
- all 4 are simply duplicating existing behaviour, but perhaps we can get a more optimal version in future
- istream ctor is intended as an extension point that can then be used to create free/static functions to work with any future data source (vector), while the path ctor is a convenience function for the common case (from file)
-- roundtripping namespaces requires modifications of the parser used for the entire worksheet as there does not appear to be a way to track the namespace changes without listening/registering for the event. This (ofcourse) breaks lots of other things...
-- custom_heights was the only test sheet where the integral value was being saved with a trailing ".0"
-- Updated tests to expect the new values
-- added the new property "defaultColWidth"
-- tolower takes chars and returns chars, types are int because C only deals with ints
-- format parameter is size_t but there is no std parsing function that returns size_t. stoull is used instead as the widest alternative, and then the cast is applied to suppress the conversion warnings
-- sqref is a block of selected cells containing the active_cell (normally is just == active_cell)
-- active cell is the selected vell in this selection/view/pane
-- inactive selections use the top-left cell as the active_cell
-- NOTE: It doesn't seem likely that these should be 'A1' in all cases (set to 'A1' because current tests demanded it). Purpose of this parameter needs clarification
-- NOTE: [xlnt::selection] needs appropriate ctor's once the purpose of the parameters can be clarified
-- additional tests to cover both variants of the set function
-- additional tests to cover hyper links on cells with non-string data
-- modified hyper link set function to handle cells with non-string data
-- fixed test behaviour for a cell with no value (value is set to the string form of the link. Behaviour copied from Excel 2010)
-- Resolves two test failures caused by a crash when setting the title to the existing value removing the sheet from the 'sheet_title_rel_id_map_'
-- added empty title check
