increase CatrobatLanguageVersion

after changing back to XStream, we have forgotten to update the catrobatlanguageversion xml field from 0.3 to 0.4 - there are programs with 0.3 that do work, and others don't.

an update to 0.4 is needed also for catroid.org to check that only programs are uploaded which are supported by the current catroid version (the one to download from catroid.org and developer.catrobat.org)

single ui test of MainMenuActivityTest (including a test with catrobatlanguageVersion): http://catrobatgw.ist.tugraz.at:8080/job/Catroid-single-UI-test/385/
source/junit tests: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-custom-branch-test-source-and-jUnit-tests-only/35/