refactor and test FLPs

refactor and test FLPs
FLPs now dynamically allocate the list of all_matches, which
has the bonus of not needing to pass in the size of the two
sequences that will be seqcomped.
I renamed win_num to size to make it more constent with other container
classes.
Also file_load and file_save were renamed to load and save, again
to be more consistent.
Lastly, I do make sure that I can construct FLPs and save and load them.