fix note types with missing reqs
cards must be removed from filtered decks before they're buried

if not, removeLrn() resets due=odue and odue=0, leading to an invalid
delay calculation when they're later reviewed in the filtered deck

to fix this we'll need to make the same changes required to support
learning cards retaining their state when being emptied from a
filtered deck
disable plastique theme on osx as possible crash fix
further simplify augmented httplib2 conn_request
recover from a corrupt prefs.db that fails to load at all
don't open log for export or upgrade, only regular+sync
make sure we don't 'fix' req for cloze type
don't bother logging sortCards()
log media sanity
rotate log file when it hits 10MB
catch invalid file encodings in media check & sync