* some style in editor changed
* opti: the display of header
* fix Cursor disappear when use arrow down/up switch between headers #867
* add a add_close svg icon
* style opti
* fix#625
* update changelog
* fix error when selection in not in edit area
* also fix double click front icon and error happen
* fix error when click front icons and toolbars of table
* rebase master
* update some codes
* null check in all selection.getCursorRange method
* add maskColor variable
* update roadmap, remove note features