can now fetch the whole handbook from the database
implemented get and insert for category and article. can also get multiple articles
some change
Merge branch 'master' into database and changed category field from title to name

Conflicts:
	UbiLearnProject/src/no/ntnu/stud/ubilearn/db/DatabaseHandler.java
	UbiLearnProject/src/no/ntnu/stud/ubilearn/fragments/wiki/Article.java
	UbiLearnProject/src/no/ntnu/stud/ubilearn/fragments/wiki/Category.java