Updated the macosx backed figure manager show function to bring the
figure to the front upon execution.
insert deprecation warning for set_graylevel
add documentation of graylevel deprecation
points_in_path etc. should return bool.

Fix #3824
Merge pull request #3812 from jbmohler/deprecate_graylevel

API : insert deprecation warning for set_graylevel
Merge pull request #2743 from cimarronm/macosx_show_orderfront

Updated the macosx backed figure manager show function to bring the window to the front.
Merge pull request #3824 from mdboom/contains-bool

Path.contains_points() returns a uint8 array instead of a bool array