Updated sample.
Comments style fix.
Added styling for placeholder widget frame.
Old placeholder plugin removed.
Temp plugin name placeholder2 renamed to target placeholder.
Further renaming.
Code cleanup.
Call CKEDITOR.addCss only once for all editor instances.
Use cke_placeholder class to style placeholder for better backward compatibility and easier styling.
Minor cleanup.
We don't need a default name since it's empty.
Switched to the 'toolbar' language entry which we used in previous version and removed 'Create' fragment, because now it may also be used to edit placeholder.
Changelog entry.
Merge branch 't/10862' into major
Various changes to how enter modes are determined:

* when active filter is set the default enter modes are checked in the first place,
* blockless nested editables have always enter mode BR,
* nestedEditable.enterMode and shiftEnterMode properties were introduced.
Added some minor comment.
Changelog entry.
Merge branch 't/10881' into major
Fixed addExternal when no file name is provided.
Fixed the case where addExternal is missing the file name and the path doesn't include it as well.