Fixup uncaught TypeError in DOMUtils.isEmpty

this is caused by missing braces which ends up in a different evaluated operator precedence
this bug only occurs if no schema was set, have a look at the unit tests
add a function to unregister a specific format by name.
Fixed bug where tabfocus wouldn't tab properly to other adjacent editor instances.
Fixed a few jscs issues.
Fixed bug where the DOMUtils setStyles wouldn't properly removed or update the data-mce-style attribute.
Fixed bug where dialog select boxes would be placed incorrectly if document.body wasn't statically positioned.
Fixed so the default action of windows closing can be prevented by blocking the default action of the close event.
Fixed so nodeChange and focus of the editor isn't automatically performed when opening sub dialogs.
Fixed issue with modal blocker element being removed even if close default event is blocked.
Merge pull request #419 from skrings/isempty_with_non_empty_elements

Fixup uncaught TypeError in DOMUtils.isEmpty
Fixed so nodeChange event gets fired when taping on iOS.
Merge pull request #421 from nhammadi/master

add a function to unregister a specific format by name.
Merge branch 'master' of github.com:tinymce/tinymce
Fixed whitespace issues
Fixed bug where pasting would sometimes scroll to the top of page if the user was using the autoresize plugin.
Fixed ascii only build issue for plugins.
Fixed bug where caret wouldn't be properly rendered by Chrome when clicking on the iframes documentElement.
Some more work on the caret rendering bug on Chrome.
Suppress eslint error.
fix for pasting word content with headings between lists