Allow option to have final iteration count to be stored in a text file

[joshhting]

This would allow us to run the rrt a bunch of times and collect the iteration counts for each one in one place, which could be useful for comparing the efficiency of a new implementation to that of an old one.

[justbuchanan]

I think this would go well as a small gui-less test program. We could have it initialize a 2d space with obstacles and parameters specified on the command line, then print out stats to stdout.

[joshhting]

If we could also store the amount of time it took to complete a run in the file, that could be a more useful measure of its efficiency as well.