[#43] Turn QuestionView base class into a LinearLayout

* Split layout from java code
* Add corresponding layout file
[#43] Add FreetextQuestionView, extending QuestionView

* Update question header layout, so the subclasses <include> this resource
* Add freetext_question_view layout file
[#67] Fix transmissions query

* Add missing columns
[#67] Use boolean type for include attribute

* Avoid using String for flags!
* In the DB, store 1 or 0
[#43] Add MediaQuestionView and its corresponding layout file