Merge pull request #524 from philippwiesemann/fix-builder-minimal-wxpython

ENH: Fix ImportError if old wxpython is installed
BF: fix automated import of gamma for known monitors

In version 1.80.00 there was a bug for certain monitor objects due to
confusion between getGamm() and getGammaGrid()

Now getGammaGrid() takes preference, but getGamma() is used as fall-back and
tests have been added to the test suite to prevent any further regression
on this
ENH: added demo for CRS bits_sharp and a script to run getLumSeries from monitors
TESTS: prevent psychopy from setting hardware gamma table on virtual linux

this means we can run more tests on Travis-CI (just skipping the problem
line in the psychopy lib itself)
FF: last commit failed to import os but it was needed (sorry)
TESTS: more explicit test for the Travis environment than using xvfb
TESTS: fixes to testing under Travis
Merge branch 'master' of https://github.com/lindeloev/psychopy

Merging upstream master into the old lindeloev/master
BF: fixed logic in _baseVisualStim.contrast when useShaders=False
DOC: Added documentation to _baseVisualStim.win
RF: reduced code redundancy for visual logging by making a logAttrib tool.
ENH: Add 'delay_offset' setting to iohub AnalogIn

Added delay_offset to analogInput iohub device. This can be set in the
device config settings or by using the setDelayOffset() method of the
AnalogInput device.

delay_offset is in sec.msec format, and is added to the calculated iohub
time and subtracted from the internally calculated delay field for
analog input events.

Default is 0.0
ADD: ioHub ioSync MCU device

ioSync integrated into ioHub Framework.

Also have 2 test scripts in demos/coder/iohub_extended/mcu

Still a work in progress.
ENH: Added some docs (incomplete)
Merge branch 'master' of git://github.com/psychopy/psychopy
ENH: added new SMI API func support
TESTS: fixed the attempt to test for Travis using .lower()

On other systems os.environ.get('TRAVIS') returns None, which can't be made lower()
TESTS: another variation on _travisTesting

handles None as well as possible system-dependent variation in 'true', 'True', 'TRUE' (
ENH: added first attempt at option for selecting rows from a conditions file
Merge branch 'master' of git://github.com/psychopy/psychopy

Merge: should fix testing?