Multi filt bagle models

[SRemulla]

Incorporates multi-filter capabilities for the bagle models inside the saved photometry.

• The bagle model parameters are now saved inside a BinTableHDU, as the fits header was too small to allow more filters
• filter_dict is now required for refine_binary_events
• lightcurves.py functions now require filter_dict

[nsabrams]

All changes look good