Extension manager: First draft of the extension class
Extension manager: implemented more extension info and basic repository access
Merge branch 'master' into extension_manager
Extension manager: add language file and simple admin component
Extension manager: fix install dir for templates
Extension manager: Use getInfo() when no info.txt is available
Extension manager: Improve update check
Extension manager: implement uninstall, canModify and install/update
Extension manager: Implement extension table

This uses a lot of code and the whole design from the previous extension
manager implementation.
Merge branch 'extension_manager' of github.com:splitbrain/dokuwiki into extension_manager

* 'extension_manager' of github.com:splitbrain/dokuwiki:
  Extension manager: Implement extension table
  Extension manager: implement uninstall, canModify and install/update
  Extension manager: Improve update check
  Extension manager: Use getInfo() when no info.txt is available
  Extension manager: fix install dir for templates
  Extension manager: add language file and simple admin component
  Extension manager: implemented more extension info and basic repository access
  Extension manager: First draft of the extension class
added tabURL builder
fixed screenshot height
fixed typo in define
added connectivity recheck
various gui fixes
added tab navigation
moved display stuff to gui class, added template list
added intros
removed test repository again
translated error message