Remove #menu_back div

Fix RTL dir display bug (eg. when arabic language activated)
Revert "Remove #menu_back div"

This reverts commit c1cff30146d9b7f810cf9bec2a220a0ac1321ca9.
Fix #menuback display on the right

When RTL dir (eg. arabic language)
Bugfix JS error Calendar._TT is undefined

set calendar lang file to english if not available in the locale
Update jscalendar i18n files

- add new languages
- complete some of the incomplete files
- UTF8
calendar-el.js
Revert "calendar-el.js"

This reverts commit 0447b4ff886da52941a783acb1b33768ef1b59ba.
calendar-el.js
Fix jscalendar i18n files

- UTF8
- comment locale short month names
- replace by english short month names (Calendar._SMN)
Add jscalendar i18n file for Chinese
Bugfix TinyMCE loading if i18n file not found

- verify i18n file exists, if not load english
calendar-pt.js

- replace calendar-pt.js with calendar-br.js
- note "br" is for Breton and NOT Brazil...
Fix jscalendar i18n files (2)

- UTF8
- Format TT_DATE_FORMAT
- Add missing data in english (weekend is undefined)
- Fix broken strings (_TT is undefined)
Add tinymce i18n files
Fix jscalendar deutsch TT_DATE_FORMAT
Version 2.5.1 update