fix: tr. 599 (assign expr_list to def should yield an error)
test for tr.599

Conflicts:
	Tst/Short/ok_s.lst
test resuls for tr.599 fixes
fix: setting currRingHdl after rKill

Conflicts:
	Singular/ipshell.cc
chg: simplify rFindHdl
fix: grobcov.lib: types
chg: description for farey
add; ref to rvar in section var
fix: harden flatten for illegal calls flatten(<ideal>)
fix: tr.604 (primdecGTZ for small primes)
fix: tr.604 (G.Pfister)
tests for tr.604
fix: path for factory/libfac pacakages
chg: ssi attributes
fix: ssi attributes p1