Fixed the queryset filters using a proper reduce in the ConcurrencyActionMixin class, the previous code was not working when more than 1 object was selected in the list, also using a .count() on the queryset rather then len() for efficiency as we o not need the qs data, #18
Merge remote-tracking branch 'origin/pull-requests/20' into develop
fixes #20. thx tdruez
updates travis to django 1.6b1