Made circular feature-finding mask conform to MATLAB code; removed my obnoxious comment
Increased maximum subnet iteration count. It should not be hard-coded!
Made identification a little nicer: no in-place image modification, and
no particles too close to image edges (which was leading to unchecked
array out-of-bounds)
Merge branch 'numba' of https://github.com/nkeim/trackpy into numba