TESTS: several adjustments
TESTS: adjust travis install for pyserial pycrsltd
Merge pull request #608 from jeremygray/master

test tweaks and BF for rating scale component
BF, TESTS: fix visual.BufferImageStim, make visual tests

- switch to inherit from ImageStim, remove _tex code
- add visual tests and .png's
Merge pull request #609 from jeremygray/master

BF, TESTS: fix and simplify visual.BufferImageStim, add tests
TESTS: higher crit for test_bufferimage

- was failing on travis at crit=5
- BufferImage is not pixel-perfect; best with window in norm units, others vary
Merge pull request #610 from jeremygray/master

TESTS: higher crit for test_bufferimage
ENH: setGammaRamp can now cope with 256x3 or 3x256
ENH: work on BitsSharp integration. Checks and loads/save identityLUT on init
BF: If the BitsSharp is not found don't try to get its info
TESTS: remove the outdated tests from crs package
Merge branch 'master' of git://github.com/psychopy/psychopy