Update to TinyMCE 4.x
TinyMCE 4.0.24
Update to TinyMCE 4.x
Make TinyMCE4 buttons smaller
Fix Spell button with TinyMCE4
Allow <> characters in spellchecking text
Fix incorrect handling of HTML comments in messages sanitization code (#1489904)
Fix wrong set-listmode command (button) status set by getunread request
Fix so current page is reset on list-mode change (#1489907)
Limit cache data size to avoid database errors
Don't list empty (nil) metadata entries to save memory anc caching space
If search string cannot be converted to ASCII (result is an empty string) use the original string (#1489911)
Fix message un-selection on the list (#1489906)
Fix debug output
Add option to suppress session data writes to DB
Merge branch 'master' of github.com:roundcube/roundcubemail
Improve performance of sort_folder_list() method.

Now sorting 25k folders takes around 3 seconds.
Bring back forcing of string type for folders list items (removed unintentionally by last commit)
CS fixes
Silence possible PHP Warning: file_exists(): open_basedir restriction in effect.