MSVC compiler support [patch 4]: sepchar definition

[Michael Goffioul]

Defines sepchar correctly under MSVC.

Index: configure.in
===================================================================
RCS file: /cvs/octave/configure.in,v
retrieving revision 1.526
diff -p -c -r1.526 configure.in
*** configure.in        13 Oct 2006 18:11:26 -0000      1.526
--- configure.in        17 Oct 2006 11:07:41 -0000
*************** AC_ARG_WITH(sepchar,
*** 52,58 ****
  case $with_sepchar in
    yes | "")
      case "$canonical_host_type" in
!       *-*-mingw*)
        sepchar=';'
          ;;
        esac
--- 66,72 ----
  case $with_sepchar in
    yes | "")
      case "$canonical_host_type" in
!       *-*-mingw* | *-*-msdos)
        sepchar=';'
          ;;
        esac