flownav: a few performance tweaks to the main loop.
added a new message type 'ttc' to build
Implemented a simple datalog with custom message types
added ttcplotter for dynamic plotting of flownav data
multi-keypoint plotting implemented. fixed knnmatch bug.
tons of refactoring; added video looping

moved all scripts except datalogger into /src
dataplotter: added wait for publisher
dataplotter: separate keypoint plotting. buggy legend/colors.
dataplotter: keypoint tracking/proper labeling implemented
Merge branch 'datalogger'

Merged all changes from creating the dataplotter script to the master branch

Conflicts:
	src/main.py
	src/scale_matching.py