Make min() and max() handle vector argument

This patch adds the ability for max() and min() to take one single vector as argument. The max (or min) element of that vector is returned if the vector contains at least one element.
bugfix: Forgot to add csg as a known filetype
Offset bug regression test
Bugfix: Offset with rounded join_type calculated fragments incorrectly for delta < 1
Tests for min()/max()
Moved to the Heavy group
bugfix: Dumptest failed to dump the highlight modifier
Merge pull request #796 from OskarLinde/offset_bugfix

Offset bug with delta < 1
Merge pull request #785 from OskarLinde/vector_min_max

Make min() and max() handle vector argument
bugfix: Don't try to export if a root geometry wasn't created
Updated pngs after merging unstable
Mac fix: Only use NSLog when GUI launched
Issue #582 was fixed sometime during the unstable branch refactoring
#593 was fixed by #608
#541 was fixed during unstable refactoring
CGAL-4.4 fixed some issues
Correction: It wasn't fixed in CGAL after all, it was fixed somewhere in our code