* configure.ac, rcfile.c:  Add support for an alternate rcfilename at configure time.  Maybe this
          should become a command line option some day, but I don't see the need currently.  Start of   
          fix for Savannah bug #24128: Add nanorc support to win32 platform.



git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@4314 35c25a1d-7b9e-4130-9fde-d3aeb78583b8