first steps towards padding
'b' now loads a comparison image.  This image is loaded into the previous panel.  TAB takes you back to the image you were first examinig.  'b' again blinks back to the comparison image.  selecting 'b' while on a comparison image loads a new comparison image.  This last feature is not yet test so likely doesn't work yet.
added 'comparitor' loading with 'b' and new-comparitor with 'n'.  Also fixxed planted_mag_check.
Merge remote-tracking branch 'origin/padding'
added two scripts to help compute the efficiency from input .match files
Get a summary of orbits associated with a directory of .mpc files
A module to convert mpc formated time strings into astropy.time.Time objects
changed import of mpc.Time into mpc_time.Time to remove circular reference