ctypes bindings for LevelDB

The existing three LevelDB interfaces (py-leveldb, cpy-leveldb, plyvel) use the Python C API and compile Python modules that work with LevelDB's C++ interface. This Python module simply uses the ctypes library to LevelDB's C interface - making it more portable across Python implementations and easier to install and distribute.

leveldb-py:

Sample Usage

import leveldb

db = leveldb.DB("/path/to/db", create_if_missing=True)
db.put("key", "value")
print db.get("key")

for key, value in db:
  print key, value