GoldsteinUnwrap2D_r​1

This is an update of Bruce Spottiswoode's 2D phase unwrapping algorithms. This version runs much faster. This was partly done by cleaning up the decision logic.
Also, it matches +/- residues by having the search box size by the outer loop and the residue index being the inner loop. (The reverse of the original.) This should find closer matches, on average, but produces different results.
Code organization was modified to more closely match the "Quality guided" phase unwrapping alternative.