View the behavior video with a superimposed rectangular box in the upper left corner that indicates whether there is a lick at a given moment

@kimtonyhyun @jmaxey @forea 
The .m file reads the behavior video and the lick_source(text file that is synced to the behavior camera that captures lick events in a 0-1 format) at the same time. For each frame, it displays the current frame of the behavior video together with a rectangular box on the top left (of size 60x60) that is black when there is not any licks(lick_source has a 0 for the corresponding frame) and turns white for the frames where there is a lick(lick_source has a 1 for the corresponding frame).
Can we use a different name, other than `image`? That will shadow Matlab's built-in function also called `image`. Suggestion: `frame`.