Implemented disk reading once lsh limit is reached

Also now writing lsh tables to ../tmp/lsh subdirectory, in case other stuff is being written to tmp
I decided to use a subdir instead of just the tmp dir to avoid dealing with whatever other files may or may not be written to tmp.

Question about teardown, why not change it so it does " rm -r '/tmp/' "
so it deletes the entire tmp folder? That way we need not worry about cleaning up specific subfolders when dan is finished running.