Added working tesseract path tracer
Added some of the documentation
Commit before surgery on the click_node method
Made "add_to_path" and "remove_from_path" separate functions from "click_node"
Added "clear_path" function andd button
Added stupid brute-force path finder
Broke out the id-to-node mapping from find_randumb
Added THE PATTERN which now constrains manual path finding and find_randumb.
Added path searching to the perl script which generates the node matrix.
Rearranged so that the search code goes at the top
Backtracking search which doesn't work (or might work if lucky and left for
a very long time.)
Does repeated runs of the backtrack search.
Changed node labels from coordinates to class indices (C1, B2, etc.)
Unfortunately, these don't match the labels I've been using for analysis.
Moved the search code out of tessgraph.pl
Renamed tess_fg_data.js to avoid overwriting tessgraph.js again
New constraint category, 'line'.  Changed the checkbox to a select control for
choosing a constraint.  tessgraph.pl now outputs a map of related nodes as
well as the json.
Recursive maps in both directions from B->E, E->B, C->E, C->B
Maps can now be programmed with class strings ie "BCDEDC", avoid self-
intersection and have a condensed output format with no coordinates.
Evened up spacing of map sequences
Each set of maps now collects which endpoints can be reached from each of the start nodes.