replace factory by a recent version from Singular github snapshot
factory now depends hard on ntl and gftable file names changed
libfac_version is now defined in a header and not as a symbol.
replaced factory's initializeGMP with a dummy
removed unnecessary patch
patch no longer necessary (is empty)
update check for gftables presence
starting to fix pull/126, which initiates the use of version 4 of factory+libfac
fixing pull/126, part 2
fixing pull/126, part 3
fixing pull/126, part 3; a flint test needs a lot of memory
fixing pull/126, part 4
start adapting release of factory 4.0.0

The problem solved was that it didn't include the needed m4
macros.

Wait for libfac 4.0.0 to be released.
fixing pull/126, part 4; disable some slow FLINT tests
Merge branch 'pull/126' of github.com:DanGrayson/M2 into pull/126
fixing pull/126, part 5; improve check-configure makefile
fixing pull/126, part 6

the latest factory factors polynomials in a different order,
so we fix a test
fixing pull/126, part 7

disable another FLINT test
fixing pull/126, part 8

factorization order changes, so update a test
fix an example using Normaliz

... now that we've upgraded to the latest version.  The ordering of rows
turns out to be different.
fix SL install instructions
Merge branch 'pull/126' into pull-126-factory-4-0-0