aded imu_tools submodule
refactored the xor checksum loops
Merge branch 'master' of github.com:ut-ras/IGVC2014
removed code to get gps and ins, as we are not using them

if you need the code, reverse this commit
fixed indentation bug that rate-limited the driver to 6.6hz
removed unneeded global
converted the read_data function to use readline
refactored init process to use a 'const' structure of commands to send
refactored main loop
increased sample rate to 200 (imu limited)
fixes issue #19