Fixes stuck grid when last genre box unchecked

Adds removeFilter function which allows the removal of filters
as opposed to previous version which only allowed updates,
causing genres to be defined as [], admitting no matches
instead of all matches
Switches data transfer between worker and main thread to blobs

Blobs allow a theoretically infinite amount of data to be shared
as opposed to the ~200KB of plaintext.

Removes extra line in reminders.pl causing email reminders to fail due
to mismatched columns and values in DB insertion.