Use framerate from Vicon to initialize frame dt + small README updates
Adds compilation to the README
Updates the readme

Calibration routine now can be run from any location
Fix major bug in 784813b, need to get a frame before using GetFrameRate

Also updating the frame_time calculation so that the frame times are
close to actual clock time with the jitter filtered out.
Merge branch 'master' of github.com:kartikmohta/vicon

Conflicts:
	README.md