fix our pari Makefile.in so it doesn't mask error return codes

from pari's Configure script
Merge branch 'master' of github.com:Macaulay2/M2
amend INSTALL for cygwin
Merge branch 'master' of github.com:Macaulay2/M2
Added new function 'antipode' to handle transpose of a matrix

over rings with skew commuting variables.
update INSTALL instructions for Mac OS X
fix the Makefile for pari, to improve recent changes
Merge branch 'master' of github.com:Macaulay2/M2

Conflicts:
	M2/libraries/pari/Makefile.in
fix a Makefile