Minor docs fix.
Initialized widget and widgetcaption plugins.
Fixed click on non-editable block should select it as a whole.
Fixed editable focus apply when inside of nested editable element.
Fixed backspace/del key behavior around non-editable element - to skip from removing it.
Basic widgets architecture.
Update necessary DOM properties of the widget.
Revert "Update necessary DOM properties of the widget."

This reverts commit 5ef8156e6a33991c4653f3f3ba33d2121f054700.
Updated widgets sample.
Create editor.widgets quickly.
Widget wrapper's attributes and styles.
Added basic skeleton of propspanel plugin.
Initialize widgets model.
Small correction to previous commit.
Initialize editables inside widget.
Registered the widget editables in the focus manager.
Moved styling out of the wrapper, which must be neutral.
Use the "contentDom" event.
Introduced widget outline & custom selection.
Fixed selection lock when cursor moved into nested editable.