Fix issue#485

Inserted notification dialog for community button.
Merge branch 'master' into issue#485
Merge branch 'master' into issue#485
Detect wrong assert messages with empty string or with delta value
Merge pull request #503 from Catrobat/FixAssertionErrorMessageTest

Detect wrong assert messages with empty string or with delta value.
Merge pull request #528 from Catrobat/issue#485

Issue#485
 refactored file to string partly
schaut nur er an