Inline topographical order into findVerticalSeam()
Inline adj() into findVerticalSeam()

This avoids the cost of making a width*height queues. Also remove
topological-sort debugging methods as they are no longer useful.
Cache search vectors as private instance variables

This avoids allocation costs between calls to find*() and factors out initialization code.
Make argmin work on more general ranges

This will make it easier to use in case I decide to rewrite findHorizontalSeam()
General clean up of findVerticalSeam()
Remove zombie method that doesn't work
Directly implement findHorizontalSeam() rather than transposing twice
Fix typo in method call signatures in new findHorizontalSeam implementation
Customize the path-finding method for horizontal and vertical
remove no-longer useful debug methods
Move explanatory comment to outside the method
Move method definitions around for easier reading
Write javadocs for all public methods
More granular memory management to improve testing scores
Add the grade the last committed version of SeamCarver.java got
Shorten common directory names