Update joomla.rb

Added more matches for Joomla versions 2.5.x
Update joomla.rb

Added 3.0.x and 3.1.x versions.
Update dublin_core.rb
Fixed a 'crucial typo' in wordpress.rb
Update pligg-cms.rb
Update ATutor.rb
Update AContent.rb
Update CouchPotato.rb
Merge pull request #111 from pvdl/master

Added latest Joomla versions.