PROBPLUGIN-97: Fixed code to check whether an invariant is defined in the current machine or an abstract one.
State view: The filter button is now initially activated
add progress bar to model checking dialog
merged develop
improve output in model checking dialog
try and adapt Model Checking Dialog text

hope it works

Signed-off-by: Michael Leuschel <leuschel@cs.uni-duesseldorf.de>
Merge branch 'develop' into rodin3