add msys2 environment/tools option, use seprate post-install script to finalize install * src/msys2-bash.mk: new file * src/msys2-coreutils.mk: new file * src/msys2-diffutils.mk: new file * src/msys2-dos2unix.mk: new file * src/msys2-filesystem.mk: new file * src/msys2-findutils.mk: new file * src/msys2-gawk.mk: new file * src/msys2-gcc-libs.mk: new file * src/msys2-gmp.mk: new file * src/msys2-gnupg.mk: new file * src/msys2-grep.mk: new file * src/msys2-gzip.mk: new file * src/msys2-icu.mk: new file * src/msys2-info.mk: new file * src/msys2-less.mk: new file * src/msys2-libassuan.mk: new file * src/msys2-libbz2.mk: new file * src/msys2-libexpat.mk: new file * src/msys2-libgpg-error.mk: new file * src/msys2-libgpgme.mk: new file * src/msys2-libiconv.mk: new file * src/msys2-libidn2.mk: new file * src/msys2-libintl.mk: new file * src/msys2-liblzma.mk: new file * src/msys2-libmetalink.mk: new file * src/msys2-libopenssl.mk: new file * src/msys2-libpcre.mk: new file * src/msys2-libpsl.mk: new file * src/msys2-libreadline.mk: new file * src/msys2-libunistring.mk: new file * src/msys2-libutil-linux.mk: new file * src/msys2-libxml2.mk: new file * src/msys2-make.mk: new file * src/msys2-mintty.mk: new file * src/msys2-ncurses.mk: new file * src/msys2-pacman-mirrors.mk: new file * src/msys2-pacman.mk: new file * src/msys2-patch.mk: new file * src/msys2-runtime.mk: new file * src/msys2-sed.mk: new file * src/msys2-tar.mk: new file * src/msys2-unzip.mk: new file * src/msys2-wget.mk: new file * src/msys2-zip.mk: new file * src/msys2-zlib.mk: new file * src/msys2-mpfr.mk: new file * src/msys2-libsqlite.mk: new file * src/msys2-keyring.mk: new file * src/msys2-libffi.mk: new file * src/msys2-libgnutls.mk: new file * src/msys2-libhogweed.mk: new file * src/msys2-libksba.mk: new file * src/msys2-libnettle.mk: new file * src/msys2-libnpth.mk: new file * src/msys2-libp11-kit.mk: new file * src/msys2-libtasn1.mk: new file * src/src-msys2-bash.mk: new file * src/src-msys2-coreutils.mk: new file * src/src-msys2-diffutils.mk: new file * src/src-msys2-dos2unix.mk: new file * src/src-msys2-filesystem.mk: new file * src/src-msys2-findutils.mk: new file * src/src-msys2-gawk.mk: new file * src/src-msys2-gcc-libs.mk: new file * src/src-msys2-gmp.mk: new file * src/src-msys2-gnupg.mk: new file * src/src-msys2-grep.mk: new file * src/src-msys2-gzip.mk: new file * src/src-msys2-icu.mk: new file * src/src-msys2-info.mk: new file * src/src-msys2-keyring.mk: new file * src/src-msys2-less.mk: new file * src/src-msys2-libassuan.mk: new file * src/src-msys2-libbz2.mk: new file * src/src-msys2-libexpat.mk: new file * src/src-msys2-libffi.mk: new file * src/src-msys2-libgcrypt.mk: new file * src/src-msys2-libgnutls.mk: new file * src/src-msys2-libgpg-error.mk: new file * src/src-msys2-libgpgme.mk: new file * src/src-msys2-libhogweed.mk: new file * src/src-msys2-libiconv.mk: new file * src/src-msys2-libidn2.mk: new file * src/src-msys2-libintl.mk: new file * src/src-msys2-libksba.mk: new file * src/src-msys2-liblzma.mk: new file * src/src-msys2-libmetalink.mk: new file * src/src-msys2-libnettle.mk: new file * src/src-msys2-libnpth.mk: new file * src/src-msys2-libopenssl.mk: new file * src/src-msys2-libp11-kit.mk: new file * src/src-msys2-libpcre.mk: new file * src/src-msys2-libpsl.mk: new file * src/src-msys2-libreadline.mk: new file * src/src-msys2-libsqlite.mk: new file * src/src-msys2-libtasn1.mk: new file * src/src-msys2-libunistring.mk: new file * src/src-msys2-libutil-linux.mk: new file * src/src-msys2-libxml2.mk: new file * src/src-msys2-make.mk: new file * src/src-msys2-mintty.mk: new file * src/src-msys2-mpfr.mk: new file * src/src-msys2-ncurses.mk: new file * src/src-msys2-pacman-mirrors.mk: new file * src/src-msys2-pacman.mk: new file * src/src-msys2-patch.mk: new file * src/src-msys2-runtime.mk: new file * src/src-msys2-sed.mk: new file * src/src-msys2-tar.mk: new file * src/src-msys2-unzip.mk: new file * src/src-msys2-wget.mk: new file * src/src-msys2-zip.mk: new file * src/src-msys2-zlib.mk: new file * Makefile.in: add msys2 vars and base rules * index.html: ref new msys2 targets * dist-files.mk: added refs to new msys2 mk files * binary-dist-rules.mk: added conditional msys/msys2 dist files, post-install.bat * configure.ac: added --with-msys2 option * installer-files/post-install.bat: new file * tools/makeinst-script.sh.in: call post-install.bat instead of fc_update and octave, and use nsExec to hide comd windows while executing it * tools/msys2-install.py; new file * installer-files/cmdshell.bat, installer-files/fc_update.bat, installer-files/octave-firsttime.vbs, installer-files/octave.vbs: update paths when running msys2

--- a/configure.ac	Mon Aug 13 14:27:16 2018 -0400
+++ b/configure.ac	Wed Aug 15 08:05:01 2018 -0400
@@ -83,6 +83,15 @@
    esac], [USE_CCACHE=no])
 AC_SUBST(USE_CCACHE)
 
+AC_ARG_WITH([msys2],
+  [AS_HELP_STRING([--with-msys2], [use msys2 in windows distribution (default: no)])],
+  [case $withval in
+     no) USE_MSYS2=no ;;
+     yes) USE_MSYS2=yes ;;
+     *) AC_MSG_ERROR([bad value "$enableval" for --with-msys]) ;;
+   esac], [USE_MSYS2=no])
+AC_SUBST(USE_MSYS2)
+
 AC_ARG_ENABLE([windows-64],
   [AS_HELP_STRING([--disable-windows-64],
     [don't build a Windows 64 cross compiler])],