Nog wat opkuiswerk, beetje code in commentaar voor datepicker
Merge branch 'master' of https://github.com/Liestambeur/StudentSaveApp

Conflicts:
	app/src/main/java/be/kuleuven/chi/app/AddGoalPage2Activity.java
	app/src/main/java/be/kuleuven/chi/backend/AppContent.java
Merge branch 'master' of https://github.com/Liestambeur/StudentSaveApp

Conflicts:
	app/src/main/java/be/kuleuven/chi/app/AddGoalActivity.java
	app/src/main/java/be/kuleuven/chi/app/AddGoalPage1Activity.java
	app/src/main/java/be/kuleuven/chi/app/AddGoalPage2Activity.java
	app/src/main/java/be/kuleuven/chi/app/MainActivity.java
	app/src/main/java/be/kuleuven/chi/backend/categories/Goal.java
Fixes #36. Fixes #2 again. Ook wat dingen die ik vergeten mergen was...