add test file as placeholder for testing error detection in ArgueJS2
finished implementation of tests for internal function isCompatibleValue(...)
bug fix: found a bug in internal function isCompatibleValue(...) of ArgueJS2 by running unit tests; the bug was that if the parameter type is ArgueJS2.TAIL then "undefined" and "null" were accepted as default values.
rebuild minimized version of ArgueJS2 after bug fixing