Added a Sinatra Grid Rest API
  - added an _entry endpoint which can return a document from mongo
    for a schema/grid using an _id or query
  - added some helpers
  - requires json content_type, responds with json content_type
Added a test:rest RakeTask, and included it into :all, which tests
  all of the tests in test/rest
Added JsonHelpers to test/helpers, with a method to make posting objects
  to the REST api and converting JSON response to objects easier
Added rest test for the Grid Rest API
Removed unnecessary mongo and bson installation from Gemfile
Added moped to Gemfile, as it is a better mongo driver than the older mongo gem
ALL TESTS PASS

added git to modules installed in base
replaced with grid_rest_api.rb