ENH: iohub keyboard and mouse msgpump

The interval at which iohub tells Windows to pass along any new keyboard
and mouse events is now configurable.

The default interval has also been changed from 0.00375 sec to 0.001
sec.
Merge branch 'master' of git://github.com/psychopy/psychopy
ENH: ioSync keyboard device support

The ioSync,ino program can now be built with or without keyboard device
support by using #define KEYBOARD at the
beginning of the program.
Merge pull request #572 from isolver/master

ioHub and ioSync ENH
Small doc cleanups for gui.fileSaveDlg() and gui.fileOpenDlg().
Merge pull request #574 from hoechenberger/master

Small doc cleanups for gui.fileSaveDlg() and gui.fileOpenDlg().
ENH: ioSync now supports analog input thresholds

Each analog input channel can have a threshold set. If the analog input
goes above or below the threshold level for that channel, a
ThresholdEvent is created.

Can be used to set voice key or light key 'triggering' sensitivity.
Merge branch 'master' of git://github.com/psychopy/psychopy
Merge pull request #575 from isolver/master

ENH: ioSync support for analog input thresholds
Don't draw lines when lineWidth is 0.
Merge pull request #576 from nortcele/master

Don't draw lines when lineWidth is 0.
RF: adjust Builder width of component as drawn on timeline

- seems to have drifted off; looks right with this fix