controller tweak to reduce oscillation
comm: Add comm.cpp and comm.h
comm: Temporarily disable motor and PID init calls in init.cpp
comm: Commit code from a while back, before I go off breaking it more
comm: Remove comm.cpp and comm.h -- communication protocol implemented inside uart.cpp/.h
uart: Implement communcation protocol (first workings, anyway)

TODO: Remove old commented-out code from previous uart.cpp implementation, brush up on comm.txt and other bits of documentation, check for buffer overrun conditions and other safety hazards
Merge branch 'master' into commproto

Conflicts:
	avr/epiphany/init.cpp -- resolved by choosing 'master' version (conflict regarded previously commented-out functions inside init_modules()
ros: add xv11_driver package (currently in progress)
ros: edit xv11 driver to get it working and add LaserScan compatability

Thanks Forrest!
uart: Modifications made to several functions to improve operation.  Added handlers for echoing a response.
project: Added the relevant project files to ensure working project after clean pull.
clock: Moved references to clocks into separate file.  More to be added later.
Merge branch 'master' into commproto to bring in xv11_driver

* master:
  ros: edit xv11 driver to get it working and add LaserScan compatability
  ros: add xv11_driver package (currently in progress)
pid: modifications done to improve performance, including software quadrature decoding.
motor: added function to control motor velocities
uart: minor changes made

Thanks Forrest!
ros: add node "xmega_connector" with echo and set_wheel_speeds srv's

More cleanup could be had. Perhaps changing the logging methods to rospy.log*()
gitignore: add exclusions for PyCharm, just in case
xmega_connector: changed logging to rospy.logdebug
xmega_connector: echo_service also logs to rospy.log*()
xmega_connector: add send_ack() routine so that I don't have to repeat myself
python: add script to test xmega communication protocol