PathFinderPixels: added removal of already used nodes from the queue
Merge branch 'path_finder_3' of github.com:gheja/jsstuffs into path_finder_3
path_finder_pixels_demo: added interactive path-finding
PathFinderPixels: the failed path-finding is now returning an empty array
Profiler: added getString()
path_finder_pixels_demo: updated path display to use the empty arrays, added a messagebox with the result of the operation