Merge latest changes from the devices2 branch
Merge remote-tracking branch 'origin/index_refactoring' into index_refactoring

Conflicts:
	brian2/groups/group.py
Merge remote-tracking branch 'origin/index_refactoring' into index_refactoring
Merge remote-tracking branch 'origin/index_refactoring' into index_refactoring
Don't use the smallest possible integer data type (which leads to all kind of overflow issues), instead use int32 by default. Also revert the conversion of integer literals to floats.
Remove a template argument that has become obsolete
Fix a template in standalone that wasn't yet adapted to the change made in eb513b0