feat(frontend): support for automated build

Along with this work on automated builds for the frontend includes:
* Upgrade docs for various Grunt usage
* Upgrade Yeoman and generator-angular files (dev dependencies)
* Update of bower.json to custom repos with appropriate bower.json
* Support for a more flexible configuration approach on the frontend
* Moved all frontend custom styles to app/styles/main/css

BREAKING CHANGE: Since several of the development packages were updated
and code updated as a consequence it will be necessary to re-install all
bower and npm packages. This is easily done by removing

frontend/bower_components
frontend/node_modules

and then executing:

bower install & npm install
Manual merging
Merge branch 'frontend-grunt-build'