Merge pull request #55 from carcam/master

Simplifying tabs creation
Thanks Carlos
JEVENTs 3.1.0 Stable
Tony's install finder check
Carlos' simplification of tabs
Language file fixes for iCal export
JEVENTs 3.1.0 Stable 
Dates and version numbers
Add class="btn-group" to module paramters radio and booleans!
Added required fields fr the event edit page
updated en-GB.com_jevents.ini to include difficulty language settings
Update config.xml

Rearranged and updated to include difficulty attribute
Update eventsadmin.css

updated to hide fields marked with hiddenDifficulty
edit.php 

Updated to mark the class of each field and fieldset with hiddenDifficulty if its difficulty attribute is greater than the current selected difficulty.
Merge pull request #59 from owendp/master

Adds difficulty level to the JEvents configuration menu
Preselect admin user in config if none specified by user
Config option for Filter Module
Fix for alldayevent editing setting in JEvents 3.1
Bootstrap fix for radio boxes when editing existing events
Merge Owen's changes
Re-instate Owen's language file changes
Update Owen's language file change to meaningful variable name
Hide the difficulty field in Joomla 2.5
$class was not pre-set
$params-> should have been $this->component->params
Adding required fields to the configuration
Adding required fields
Added new field type for required fields
Required fields are compulsory for editing layout