Fixes display issues with the filepicker dialogs that were
converted to M.core.dialogue.

Note: These dialogue use table based layouts and the table width is not
counted in the form that it sits in. I have changed the dialogues to have
a wider width but for really small screens this causes horizontal scrolling.

The only solution for that is to rewrite all the filepicker/filemanager dialogs
to use css for layout.

Add length limitation for header, so it fits nicely in mobile devices

This reverts commit 7c271b91, 313e5851, ade4695d, and 70b4027b

Conflicts:
	theme/bootstrapbase/style/moodle.css

This was caused by changes in MDL-39851.

The filepicker was changed to use M.core.dialogue - this
patch updates the behat suite to search the changed dom for
the file picker windows closed event.

Conflicts:
	version.php

We have an alternative (pdw toolbars)
Also, allow tinymce to be collapsed down to a single row.

This is just to get the tests passing for integration purposes. Tim
may want to do a robust fix and revert this.

Items addressed
* Get rid of custom attribute srcNode
* Change extraClasses to a config only parameter.
* Change attribute fullscreen to a method.
* Restore the original window overflow value.
* Use setStyles instead of setStyle for performance.
* Tinymce end the zindex wars
* Prevent fullscreen dialogs in an iframe (tinymce managefiles plugin).
* tinymce: Cross browser fix for zindex on popups
* Use CSS for overflow changes (easier to keep track of the previous state).
* Fix Coding style for css changes