MongoDB setup.

Added:

* mongodb configuration
* re-usable functions for CRUD operations
* jsdoc documentation for each file changed
* mongodb package added to package.json
* migration for users table, not required with mongo.
v0.0.5
Merge branch 'release/v0.0.5'
MongoDB configuration added

Added:

* mongodb package to package.json
* configuration to use mongodb
* re-usable functions on Application controller

Instructions:

* after clone this version, run `npm install` to install dependencies,
  you may want to try a new version of `mongodb` package. If so,
  after `npm install` you can run `npm install mongodb --save`