Mapping of system errors

[jasper]

COM errors map to CAPE-OPEN errors on the COBIA side. Similarly COBIA errors map to ECapeUser errors on the COM side.

Perhaps COM system errors, such as E_POINTER, E_FAIL, should map to COBIA system errors such as COBIAERR_CriticalError and COBIAERR_NullPointer.

In addition to this making sense, it also allows the test suite to test that CAPE_OPEN errors are raised instead of system errors, where expected.