Save sequence configuration + tests.
Save interpolant configuration + tests.

The read_interpolant function was already present, having been committed previously by mistake. The tests resulted in a small fix making the parameter applicable also for the inv method
Merge branch 'ptvis_mem' into working_branch

Added 'traj_min_len' as a saved key with override.

Conflicts:
	flowtracks/sequence.py
Fix: wrong file opened by sequence reading test, found by Alex.
Merge pull request #3 from yosefm/working_branch

Saving configuration. Merged with fix to the bug pointed by Alex.