First "beta" of multicorn FDW on pgxn

Hello.

I just uploaded a first version of our multicorn foreign data wrapper:
http://pgxn.org/dist/multicorn/0.0.3/
Homepage for the project is at http://multicorn.org.

It provides python bindings for foreign data wrapper through a minimalist
interface.
It is not safe (any python module could be called by a server) and not
production ready.

The following features are supported:
- Push where clauses to the python backend when possible
- Push declared columns to the python backend
- Manages the following postgresql/python types (and their corresponding
arrays):
- unicode -> varchar
- string -> bytea
- datetime/date -> timestamp/date
- dict -> hstore
- numeric -> float
- integer -> int
- User mapping are supported and appear to the python backend as regular
table options
- Some python foreign data wrappers implementation are provided, more as a
proof of concept than anything else.

If anyone has the time and/or interest to give some feedback, it would be
greatly appreciated.

--
Ronan Dunklau