For now a Dummy and disabled PGP
Missing classmethod decorator
Add missing dep
Log a error if it doesn't have methods() defined
Payment Support

PGProviders:
* Support association to system PGM and owned PGM. (Don't have each PGP link to
* a private PGM row).
* PGProviders to PGMethod registration is now fixed supporting the above using
* different relations on the PGrovider.
* PGMethod DB Code / Storage API.
* PGConfig DB Code / Storage API (Merchant configuration of a PG)
* PaymentMethod - DB Code / Storage API for Customer PM - Credit card..
* Add more debug to registration code.
* Add dummy PGP plugin

Products:
* Remove ProductMetadata and turn meta > extra - will be revised.

General:
* Support _get to filter on name by passing by_name=True to it as a kw.
* Add a _kv_rows helper to get a key, value representation of rows.
* Lots of tests
Merge branch 'master' of ssh://github.com/billingstack/billingstack