RTL for TinyMCE:
- Add _dir: 'rtl' to the TinyMCE translation object.
- Fix editor.css for RTL.
- Fix the Edit and Delete buttons position for wpview and images.
- For _mce_set_direction(), update documentation and fix adding the 'ltr' button.
Fixes #27773
Built from https://develop.svn.wordpress.org/trunk@28094


git-svn-id: http://core.svn.wordpress.org/trunk@27925 1a063a9b-81f0-0310-95a4-ce76da25c4cd