Support for CUnit 2.1-3

[cunit] cunit.pl: fix init of CU_SuiteInfo type for CUnit 2.1-3

The struct CU_SuiteInfo in CUnit has two new members.  This means we need two extra NULLs in the initilization.  This change precludes using older versions of CUnit.

There may be a way to do this with conditional compiles.  I couldn't figure it out.