Create Malt.io API (Read-write)

Create an API that will let third party clients be written against Malt.io. Required features:
- User registration
- Login (probably OAuth?)
- List users, recipes, etc
- Create and update recipes and profile info

See Cloud Endpoints, which is being released publicly soon:
http://endpoints-trusted-tester.appspot.com/

Start by reviewing the existing Malt.io project structure and the referenced Cloud Endpoints documentation. Map the requested registration, login, listing, and recipe/profile write operations to existing entry points; done means the API scope, authentication approach, and behavior for each listed operation are defined and implemented.

Written by the indexing model from the issue text.