improve SourceTest
use StringBuilder where possible
made RegEx faster
Merge pull request #935 from Catrobat/improvedSourceTests

improve SourceTests
removed japanese strings
Merge pull request #947 from Catrobat/no_japan_strings

remove japanese translation
fixed PMDWarnings.

fixed md5 checksum error.
Merge pull request #950 from Catrobat/PMDWarningsPart9

fixed PMDWarnings.
issue#813 Added new testcase, fixed bug
Merge pull request #945 from Catrobat/issue#813

issue#813 Added new testcase, fixed bug