feat(modules) Create modularized structure of ng-devstack

feat(modules) Create modularized structure of ng-devstack:

* structure much more suited for bigger apps (each module separated into separate files)
* fixed Gulp and Karma config to reflect *.module.js file importance (it must be loaded first)

The good part is that change do not change old way - you can still do it as previous (with one file) but if you would like to separate module files - you can.