Widefield alignment

AP_align_widefield

Usage:

0. Set path to save alignments (first line in AP_align_widefield)
1. Create master alignment reference ('create_master') from average aligned VFSs from multiple animals
2. Across-day align ('new_days') using vasulature from all days of one animal
3. Across-animal align ('new_animal) using the aligned average VFS from new animal
4. Apply saved alignments to any images (specifying animal and day source)

(readme in progress)