DOC: Updated doc for "win" attribute.
consistent autoDraw and autoLog across _BaseVisualStim stimuli
RF: made a _logAttrib() method for logging. To reduce code redundancy.
Merge branch 'master' of https://github.com/psychopy/psychopy

Conflicts:
	psychopy/visual.py
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.
Merge pull request #536 from lindeloev/master

Various visual