style(project): setup basic project structure - create additional directories and update project configuration files

 - add sub-directories for services, controllers, directives, packages and vendor to app/scripts, test/spec and test/mock
 - update Gruntfile.js to watch all new subdirectories
 - update Gruntfile.js to run karma task on save of app/scripts/
 - update test/.jshintrc to allow ddescribe, iit, xdescribe, xit
 - update karma.conf.js to include new subdirectories
 - update karma.conf.js to include firebase cdn scripts (not yet included)
test(firebase): add firebase cdn files for testing purposes

Tests require cdn files, so copy locally to avoid hitting the network every time test suite runs:
- add firebase cdn files to app/scripts/vendor/firebaseConf
- update reference to files in karma.conf.js
fixt(test suite): move firebaseCore scripts out of app/scripts to fix failing tests

- move app/scripts/vendor to app/vendor to stop jshint errors in cdn files (which are not part of the test suite)
- update Gruntfile.js and karma.conf.js to reflect changed file locations

Resolves failing test suite due to undefined reference error for Firebase in angularFire cdn script.
feat(login signup): import login and signup from demo repo including tests

Create:
- login controller
- signup controller
- header controller
- login view
- signup view
- login spec
- signup spec
Update:
- index.html
- app.js
- main controller