Remove "b"s appended to some of the filenames, Melting Pot

Melting Pot:
For some reason, some of the filenames for the images
loaded into Omeka have a "b" appended to the filename - for example
2_04_08b.jpg. In each of these cases, the image contained in the JPG
file is the same as the image in the associated
(without a "b" appended to the filename) TIFF file. So these appended
"b"s were removed.
Regenerate Melting Pot MODS due to removal of appended "b"s

Removed the appended "b"s in the filenames were they occured, within
the remediated metadata (see commit 822902c0d5704de5c358353d0eba40ed3652c4aa)