Processing_GUI: improve binary receiving

Big-time rework of the routines to receive the binary data from OpenBCI
via the Arduino.  Removed the ability to do text transfer.  Now, only
does binary.  Tested for 8 channels.  Untested for 16.  Tested at 115200
kbps and at 2*115200.  Setting it to 115200 is more stable.  Changes
need to be ported to Processing_GUI_Simpler.
StreamRawData.ino: set baud rate back to 115200
Adding .gitignore to exclude logged data files
Processing_GUI: more improvements for serial comms

More tweaks to the code to improve serial comms.  Also, redefined when
the GUI decides to redraw the screen.  This helps to smooth the display
a bit, though it's not perfect.  Code now interprets and writes the
sample counter provided by OpenBCI/Arduino.
ADS1299Manager: now it streams the sample number

In each data packet, it now includes the sample index.  You can now
watch this index to see if there are any hiccups on the PC in the
reception of the data from the OpenBCI/Arduino.
OpenBCI_GUI: updated readme
Processing_GUI: changed filename
Processing_GUI_Simpler: removing uneeded headPlot.pde
Processing_GUI_Simpler: copying serial improvements

Copying over from Processing_GUI all of the improvements that were aimed
at making the serial communication more robust.  Also included is the
reading/logging of the sampleIndex provided by OpenBCI.
Processing_GUI: updated readme
Merge pull request #8 from chipaudette/master

Processing GUIs: more improvements to serial handling