Add karma for unit testing and TravisCI/SauceLabs

* add karma
  * using the following approach for combination with browserify
    * http://ngokevin.com/blog/requiring-browserify-in-karma/
  * add karma launchers for firefox and chrome
  * add two npm scripts for running karma specs with Chrome or FireFox
adapt simple-test-app-config.js for new endpoint naming and angular-translate
WIP: simple-test
add locale-config to simple-test-app-config
WIP: karma config
WIP: tdd/karma: watching works now

* add .travis.yml
  * configure for running karma specs
  * configure for running protract e2e specs on SauceLabs
    * you need to register for a SauceLabs account and set your SauceLabs credentials as environment variables in the TravisCI project settings
update .travis.yml to start a node server IN BACKGROUND
set sauce-connect=true
change protractor-conf.js for saucelabs config
travis.yml: call explicitly the run scripts (protractor and karma)
travis: run at first karma, then protractor

change 'test' script to run protractor specs
set baseUrl for protractor again

* add angular-mocks
  * as an alternative to the node based mock backend
  * can be used when wished
    * via the gulp flag 'angular-mock-backend'
    * but the node based mock backend is currently the prefered way of mocking
WIP: angular-mock for e2e specs (authentication and posts json; with working wildcard pass-through)
WIP: move mock-backend stuff to own file; make it conditional (see: http://www.base2.io/2013/10/29/conditionally-mock-http-backend/); wip: gulpfile

* enhance node based mock backend server
WIP: try to enable CORS for post method as well (for signin): FINALLY POSTS AND AUTH WORKS ;)
WIP: add body-parser