XWIKI-10713: Gadgets in my dashboard displayed below the user vertical menu in edit mode

* Caused because in Flamingo we extend on .clearfloats the definition of .clearfix which adds rules also for :before and :after
XWIKI-10802: Additional margin for gadgets inside 'My Dashboard'
XWIKI-10783: The text from "Available columns" is inconsistent

* Removed unneeded class .label, which has meaning inside Bootstrap
XWIKI-10697: Issues with buttons width when using the objects editor in full screen

* In Flamingo the button definition has changed
Merge pull request #311 from msmeria/master

XWIKI-10389: The Blog title is hardcoded in English
XWIKI-10797: Activity Stream panel:space-separated missing near RSS logo
XWIKI-10690: remove Add button if user is only allowed to add Comment
Merge pull request #312 from Pbast/patch-13

XWIKI-10690: remove Add button if user is only allowed to add Comment
XWIKI-10805: Expose XWikiDocument.translation() to the web API
[cleanup] Formatted documents using the new xar export format.
XWIKI-9567: Cannot restore document translations from recycle bin
- Not allowing to restore a translation if its main document is not restored or re-created before.
- Also displaying the document language for ease of use.
- Added tests.