create "added" graph

This simple graph shows how many new cards you have added to a deck or
collection over time.
say "notes exported", not "cards", if appropriate
Merge branch 'master' of https://github.com/sobjornstad/anki
make sure .db is initialized at start of profiles init

fixes
File "aqt/profiles.pyc", line 253, in _loadMeta
  File "aqt/profiles.pyc", line 234, in recover
AttributeError: 'ProfileManager' object has no attribute 'db'
make sure we write addon .py files as they've been uploaded