Pre-compile HTML-stripping regexes.
don't update media count when upgrading

fixes https://anki.tenderapp.com/discussions/ankidesktop/2770-error-message-while-importing-anki-1-deck-to-anki-2
change misleading note import msg
unbury from overview shouldn't unbury all decks
honor home deck's new card bury setting
support import of renamed .apkg files
tolerate windows trash errors
fix replacement of other clozes

https://anki.tenderapp.com/discussions/ankidesktop/2904-cloze-deletion-behaves-oddly-instead-of-giving-error-when-single-colon-is-used?mail_type=queue
Merge branch 'new_branch_name'
prioritize urls over text; fixes linux fm drop (#945)
remember window size for deck&model selection (#931)
make sure we escape html chars after type ans comp. (#960)
make sure we decode full traceback on addon err (#954)
strip html in duplicate check (#906)
define standard encoding for unicode (#893)

- always store media references in fields in NFC form
- always encode filenames on disk in NFC form on machines other than macs
- use relevant encoding when placing files in the media folder during syncs
  and apkg imports as well
- rename 'unused media' back to 'check media'
- check media can now automatically change media references and filename
  encodings to the correct format
add internal option to disable burying on answer
use unicode when recording
reschedule should not operate on filtered/suspended/buried

this should fix some issues with rescheduled cards ending up in an invalid
state
remove invalid line
bump sync ver to 6 (see note)

when porting this to other platforms, please ensure you have ported all
changes in sched.py after 2.0.12 first