Change localStorage to SQLite

[AdamVig]

Switch from relying on localStorage to store the few key-value pairs that the app relies on to using the more reliably persistent SQLite database.

The SQLite database will be accessed via the ngCordova wrapper Lawnchair abstraction of the Cordova SQLite plugin.

Fixes #67, a bug that would logout the user when localStorage was cleared.

[AdamVig]

The data that the app has to store:

• username : string
• password : string
• settings : object
• modules : array of objects (note: could be reduced to an array of strings)
• app_version: string

[AdamVig]

This pull request morphed into a full refactor of a lot of parts of the app. The purpose for almost all of the refactoring was to convert from using StorageService to DbFactory.

[AdamVig]

Closes #67.