issue#69: implemented 'private' keyword for variables/constants
issue#76: implemented by accident ;-)
issue #69: added private visibility to suites, constants and forks
issue #69: added success tests
fixed missing validation of call result link
Merge branch 'v0.13.x_bugfix'
Merge branch 'master' into issue69
issue69: added first JUnit test cases, added a lot of model validation
issue #69: added scoping&checking for variables in suite parameters
issue #69: added more visibility tests
issue #69: added more test cases