added build.xml (#GSOCSTCC-2/#GSOCSTCC-9)

* added: converter jar creation target
* added: test targets
changed logging settings
fixed xml encoding bug, uncommented test projects
extended utility class and moved into common
fixed endless loop
missing part of encoding fix
Changed / extended test base classes; changed Project / ProjectCode classes

* changed: functionality to get sub-testoutput-folder (BaseTestCase)
* added: option to assert zip does not contain certain files (ProjectTestCase)
* changed: tests to use BaseTestCase class
* added: Jython security settings check for test runs
* added: resource names and unused resources functionality (ProjectCode)
* changed: refactored Project, ProjectCode
improved error handling, logging; cleaning
added access to Catrobat version number
added tests for common module
added tests for converter jar

changed: MainTest to allow subclassing for JarTest
process output redirected
renamed and refactored
pydev warnings ignored; changed comments