ENH: Updated iohub demo folder structure

+ added / cleaned up ioSync demos
BF: removed imports of module (textbox.fontStore)

the module does not exist anymore.
BF: ioSync Linux auto connect
BF: Raise exception if freetype dll is not found
ioHub Docs update
updated iohub version
BF: removed unwanted commented out code
ADD: Graphics and control logic for ET validation

A Validation wrapper is not yet done, but the core classes that will be
used to support an eye tracker independent validation process is now in
place.

Could also use same code for eye tracker calibration on systems that use
psychopy graphics for calibration stim.

See the 'validation.py' demo in demos.coder.iohub.eyetracker for an
example
of how the new classes will be used to create a packaged validation
process method call for the iohub eye tracker device.

TODO:
- Calculate and display validation accuracy
- Add starting intro / menu screen and validation complete type msg
screen.
ENH: More work on eye tracker validation graphics

Now displays results at end.
Only will work with Tobii system as the missing sample filter is tibii
specific right now. ;( Will fix tomorrow.
BF: Eyetracker missing data handled uniformly

SMI, EyeLink, Tobii and LC Tech all now use the same values in the cause
of missing sample data for gaze position fields, pupil size, and status
field:

If sample IS fine, status is == 0 now for all eye trackers.

If sample is missing data:

For monocular:

gaze_x = EyeTrackerConstants.UNDEFINED
gaze_y = EyeTrackerConstants.UNDEFINED
pupil size = 0
status = 2

For binocular:

for left:
left_gaze_x = EyeTrackerConstants.UNDEFINED
left_gaze_y = EyeTrackerConstants.UNDEFINED
left_pupil size = 0
status = 20

for right:
right_gaze_x = EyeTrackerConstants.UNDEFINED
right_gaze_y = EyeTrackerConstants.UNDEFINED
right_pupil size = 0
status += 2
status field used to filter for all et models
BF: corrected instructions text.
Merge branch 'master' of git://github.com/psychopy/psychopy
ENH: Final beta version of ET Validation process.

See validation.py demo.
Merge pull request #552 from isolver/master

BF and ADD: Many iohub related changes