Create mobile app build for iOS and Android

[brylie]

We would like for GeriLife to be installed on user devices. To support this goal, let's leverage Cordova and produce both iOS and Android builds.

Task

• Ensure client code and backend code are entirely separate
  • All client interactions with the server should happen via REST or method calls
• Add MIT license to client code, leave server code as AGPL
• Ensure most/all business logic is in server code. The client should only be responsible for rendering content
• Enable mobile client builds on the project.
  • iOS
  • Android