Tests: tagged autop tests.
Added auto paragraphing for nested editable.
Fixed auto paragraphing in nested editable on enter key.
Fixed code style and added comment pointing to ticket.
Changed shouldAutoParagraph condition to check just contenteditable attribute.
Refactoring: Looking for closest editable uses getAscendant methodnow.
Tests: Added auto paragraphing tests for nested editable.
Extra check for DOM fragments in getAncestor method.
Tests: Fixed number of issues in the new test.
Tests: Fixed broken HTML comparison on IE8.
Tests: Webkit needs focus or the selection won't behave naturally.
Tests: You don't want auto paragraphing to step in.
Tests: Made enter key test more precise.
Changelog entry.
Merge branch 't/12162'
Tests: Written test checking whether snapshot is made after 25 chagnes.

Conflicts:
	tests/plugins/undo/keyboard.js
Tests: Improved.
Implemented KeyEventsStack which handle information about key events. Calling type method on uM when keydown exceed 25 for the same keyCode.
Refactoring: Added static KeyEventsStack.getKeyGroup method.
Tests: Added test which check whether undo and redo buttons are in proper state, after undo command.