ProcGUI: changed filters from 30Hz to 50Hz.

Since the impedance check happens at ~32 Hz, the old filter settings
would cut it out.  These wider settings let you focus to get a better
impedance measurement.  It also allows you to be more aligned (though
still not well-aligned) with the "concentration" frequencies.
ProcGUI: set to "normal" mode for live data acquisition
Merge pull request #17 from chipaudette/master

ProcGUI: changed filters from 30Hz to 50Hz.