Issue #1901624 by agalitsyn: Fix bad page title background in search listing && creation forms

Issue #1892162 by contact@thoro.org: Several problems with the WYSIWYG mode
Issue #1898696 by eugene.ilyin: wrong checking for multiple field on override form
Issue #1897504 by agalitsyn: Wrong tooltip position on admin/content/assets
Issue #1888478 by Malman: Javascript error - setAttribute
Issue #1895330 by agalitsyn: Add support for view modes in when loading html for wysiwyg

Asset widget:
Add asset preview in tooltip using view mode switcher.
Handle asset view mode in wysiwyg using drag&drop and view mode switcher.
Multiple bugfixes.