Appearance Model Functions

Added two appearance cost models. Both are O(size(Video)) in time
complexity. Along the lines of Animesh’s objective, was trying some
functions that search for the most similar patch but complexity is
O(Pixels^2 * Frames) unless kd trees are used so I gave up as even the
random forest one gives similar results. Might implement this later if
we feel the random forest one screws up.
Merge branch 'master' of https://github.com/animesh-garg/videoSeg

Conflicts:
	.gitignore