fix: explain monomial
fix: option in proc elim
add: doc: option(warn)
chg: listvar(all) lists Top and Current instead of only Top
fix: handle undefined rings in ssi
fix memeory leak for undef. rings in ssi
fix: ssiReadRing for dummy rings
fix: in modstd.lib: pass the correct ideal to primeTest()
Merge pull request #409 from steenpass/modstd

fix: in modstd.lib: pass the correct ideal to primeTest()