Set tab size to 4 spaces, to make is better displayed.
Changelog entry.
Merge branch 't/11809'
Fixed indentation in some of CSS files.
Fixed #11090.
Check if element is specified only on IE.
Changelog entry.
Merge branch 't/9504'
Don't update richcombo's state when it's active.
Changelog entry.
Merge branch 't/11793b'
Apply fake object's downcast filter to non-editable elements.
Changelog entry.
Merge branch 't/11850'
Added backspace handler – collapsed selection, adjacent blocks.
Added support for DEL key.
Code refactoring: general clean-up.
Code refactoring: extended comments and removed obsolete code.
Used range#checkStartOfBlock and range#moveToClosestEditablePosition instead of CKEDITOR.dom.walker to make the procedure bulletproof and maintainable (boguses, non-editables, etc.).
Changed lister event: keyup -> key, so it is executed later than other existing key listeners.