Lots of code cleanup :)
Missed a )
Constructor added
Public function defined
Extend frontend class
Refactor frontend / options classes
Code style fixes
Merge branch 'master' of https://github.com/Yoast/google-analytics-for-wordpress

Conflicts:
	frontend/class-frontend.php
Undefined variable/method fix
Basic testing methods
First basic test
Refactor options code
Merge branch 'master' of https://github.com/Yoast/google-analytics-for-wordpress