Dutch language files added
Add specific discount report
This commit will fix a common problem in CodeIgniter.
After $config['sess_time_to_update']  expires the session will be destroyed if concurrent AJAX calls are made to the framework.
Original discussion on this problem can be found on the following URL

http://stackoverflow.com/questions/7980193/codeigniter-session-bugging-out-with-ajax-calls
Added autocompletion for the customer field in the sale editing screen
Added a global expand/collapse all control for reports sections
Merge branch 'feature/lang_dutch'
Merge branch 'fix/lost_sessions'
Removed duplicated system language folders
Merge branch 'feature/discount_report'
Deleted sales can be shown again under items
Language folders renamed + fix for loading them
Added smoe translations to the nl-BE language
Autoload settings adapted