Fix issue#506

Bug fixed. The SpeakBrick does pause now if you pause the project and continues speech at resume.
Tests had to be written nearly from scratch, due to the new behavior of the SpeakBrick (now: sound files, before: text to speech output)

Jenkins test run:
http://jenkins.catrob.at/view/Catroid/job/Catroid-Multi-Job-Custom-Branch/109/