tests for modstd.lib
fix: ssi: qring+extRing
better error message: access object from other rings in newstruct
chg: make sqrf_norm_sub return non-sqrfree norm if wished
chg: do not waste non-sqrfree norm
chg: better docu and function naming
chg: move IntGenerator from facAlgFuncUtil to cf_generator
chg: added a function to compute the norm
chg: use a not necessarily squarefree norm in factorization over number fields