Add ToField and FromField instances for aeson's JSON Value
Add the toJSONField and fromJSONField functions

These can be used as the default implementations for the toField and
fromField methods for Haskell types that have a JSON representation in
PostgreSQL.
Merge pull request #79 from basvandijk/aeson

Provide aeson-based JSON support
Check type before null in FromField json instance
Bump Version to 0.3.7.0; CHANGES
Tweak CHANGES
bytestring 0.9 support #80
Merge pull request #81 from snoyberg/master

bytestring 0.9 support #80
Bump Version to 0.3.7.1; CHANGES and CONTRIBUTORS
Parse a strict ByteString to a JSON.Value directly using eitherDecodeStrict