fix: warning for option changes does not work for libsingular

(from master, currently unused as options are in libsingular, not main)
add: option(noredefine) also for export

(from master)
Merge branch 'spielwiese' into sw_fix

* spielwiese:
  fix: warning for option changes does not work for libsingular

Conflicts:
	Singular/iplib.cc
fix: porting singnal handling (win, etc.)

Conflicts:
	Singular/cntrlc.cc
chg: change omAlloc policy: OM_DEFAULT_PAGES_PER_REGION to 512 (2 MB)
add: names(int level) added

(from master)
Merge branch 'spielwiese' into sw_fix

* spielwiese:
  add: names(int level) added
  chg: change omAlloc policy: OM_DEFAULT_PAGES_PER_REGION to 512 (2 MB)
  fix: porting singnal handling (win, etc.)
  add: option(noredefine) also for export
fix: NULL deref in qideal test

NOTE: adaptation of 071e6adf671c14d7003accadcce5271a90cde970 to SW
fix: support very very long names in listvar

(from master)
Fix cleanup/creation of Singular/LIB in during out-of-source-tree building
fix: primeFactorization redone with trial dvivision/Pollard-Rho from gmp

Conflicts:

	Singular/misc_ip.cc
fix: primefactors(): result and algorithm, bound enabled again

Conflicts:

	Singular/ChangeLog
	Singular/iparith.cc
fix: primeFactorization: bound
fix: freebsd port
fix: bad condition