header on dbcore.py
reorganize dbcore into a package
tests: silence logging output
new dbcore.query module

Splitting off the Query hierarchy for easier navigation.
Keep old pluginpath mechanism for compatibility
move remaining generic Query types to dbcore.query

NumericQuery is still broken. This, of course, is the whole reason for the
change.
add `query` field to types

This is starting to get at the heart of the matter: now each type gets to
declare which Query subclass it wants to use, starting with NumericQuery.
use PathQueries declaratively

Now PathQuery is just another type-based query, just like NumericQuery.
remove superfluous py_type field from Type
Merge pull request #499 from geigerzaehler/master

Make pluginpath configuration useable
changelog/thanks for #499
Embed item data into web request
Use generators to stream web requests
Add JSON-API tests
JSON API responds with embedded items

This effectively removes the "album_ids" and "item_ids" keys from the responses
of `/item/` and `/album/`, respectively. Instead there are "albums" and "items" keys,
respectively that contain a list of JSON representations for all albums and
items.
Load development beetsplug in tests

See also a4b69767553ebc6c2447787ec9d0263050830f71
further paramaterize parse_query_part
map `comp` queries declaratively

Woohoo! More removal of special cases.
resolve FIXMEs from query refactor
undo dumb file renaming mistake