mingw port: get gdbm to compile

next: trim down value of LIBS stored in config.status by M2's configure
      to something minimal.  In particular, -lxml2 doesn't need to
      be in it, as that name is invariant and can be mentioned
      explicitly
update license info for gdbm (GPL v2 has become v3 or later)
update license info for mpir
mingw port: make mpir and pari compile; note: mpir is set to use generic non-assembler code
mingw port: make pari compile, part 2
mingw port: make pari compile, part 3
mingw port: makefile improvements
mingw64 port: make library "factory" compile
mingw64 port: get library libfac to compile
mingw64 port: get program frobby to compile
mingw64 port: get gtest to compile
mingw64 port: fix makefiles so 4ti2 compiles
mingw64 port: make program normaliz compile
mingw64 port: make program nauty compile
mingw64 port: make programs lrslib and cddplus optional; cddplus especially has problems under mingw64; make scc1 compile
mingw64 port: add configure macro AX_PROG_CC_FOR_BUILD; make Macaulay2/c build using it
fix pari makefile under mingw so it doens't put libraries in /bin
mingw64: porting in d directory
mingw64: porting in d directory
mingw64: porting in d directory