RF/BF: logging for colors. Moved logging out of helpers.setColor.
DOC: updated docstrings and comments regarding colors
RF: log=None in BaseVisualStim
RF: created setAttribute() function which will eventually replace setWithOperation() and callAttributeSetter() with a few bugfixes/enhancements.
RF: move BaseVisualStim. to setAttribute(), deprecating _set().
RF: use setAttribute() instead of setWithOperation() and callAttributeSetter() and sometimes logAttrib().
The idea is to just have setAttribute() for set*() methods and @attributeSetter for attributes.
RF: autoLog=None as default for visual stimuli.
BF: small fixes to logging
ENH: changed from name='' to name=None which defaults to "unnamed <type>"
BF: avoid logging name setting during init.
TEST: removed manual autoLog=False and log=False from stimuli/setters so that they follow default Window.autoLog behavior.
TEST: use attributeSetters instead of set*() where implemented.
RF: split out Window-related attributes/methods from BaseVisualStim to WindowMixin