TESTS: ratingscale, custommouse

more coverage, fixed a couple errors along the way
FF: import convertToPix in misc.py
TEST visual.Line, Rect, Poly
TEST: minor: mark some tests as slow, remove trailing whitespace
TEST: visual/textbox

- basically just test init so far
TEST: bf in test teardown_class
TEST: event.py

- minor whitespace cleanup of event.py
- test_event: can't test some mouse features
TEST: some were not passing in the context of others

odd, they passed by themselves with py.test -k event
TEST: key presses in test_event had pytest/travis issue

psychopy/tests/test_misc/test_event.py:73: TestPygletNorm.test_keys
INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "_pytest.main", line 72, in wrap_session
INTERNALERROR>     doit(config, session)
....
TEST: another no-go on travis-ci
Merge pull request #481 from jeremygray/master

test some more lines of code