BF: Handle case of all default metadata

can now start exp. with hdf5 saving , even if none of the exp. or
session meta data is  provided.
BF: eye tracker validation plot image

Is now saved in the directory specified with the "save_figure" kwarg of
the ValidationProcedure class. By default, this arg is None, which
results in the image being saved in the same folder as the script being
run.
BF: smi tracker.getEvents() working again
BF: (re) implemented SMI ConfigureFilter

Did it April 4th, but commit must have failed or something, as the
original change was never logged as a commit to github. ;( ??
BF: EyeTracker Validation crash

if no data could be collected for any validate point, the analysis was
crashing.
Merge branch 'master' of git://github.com/psychopy/psychopy
ADD: iohub Serial Device

Intended to be used for general purpose access to data received on a
serial port. The serial rx stream can be split into serial events by
specifying values for prefix, delimiter, and / or fixed_width
configuration options.
ENH: Added PST box support to ioHub Serial

See coder/iohub/serial/pstbox.py demo for an example.
Merge pull request #565 from isolver/master

BF and ENH: ioHub related