Knn matching of 1 frame and good matching
Storing 10 images and descriptors
Begun optical flow
calcOpticalFlow doesn't work
Optical flow works now. Hory shet.
Removed extraneous lines
The app dies if moved too much. 
Which is initially good since it knows that it can't find new features.
Removed unused activities (finally).
Now adds new features. Yey.
Rearranged logic.
Added feature track drawing
Fixed flow direction
Merge branch 'optical-flow'