Tests: Separated groups of tests with comments.
Tests: JSHint and JSCS fixes.
Switched to the new tools.range methods for better precision.
Tests: Shortened basic inline style cases and added more of them.
Tests: Added TCs for the current behavior of the styles system.
Fixed a TC when attValue is a string, but actualAttrValue != attValue - error was thrown.
Added TCs for the current behavior of the styles system.
Styles should be fully matched (including attributes and styles) to elements to which are then split and later removed.
Added note about the nature of the new styles.
Changelog entry.
Merge branch 't/12688'
Tests: Added tests for applying one font style over another.
Remove existing font style before applying new one.
Tests: Added more test cases for deep structures.
Handle the collapsed selection case, when we can't use editor.removeStyle.
Tests: Turns out that insertText is also affected by the ACF - that's because of how the text is being processed.
Tests: Added manual TC.
Tests: Test for correcting the font size.
We need to remove the empty style element because it is visible.

See http://dev.ckeditor.com/ticket/12403#comment:22
Added note about temporality of this fix.