Make build system more in alignment with how autotools work. This
will make transition easier.
* mes/module/mes/boot-0.scm.in: Update from module/mes/boot-0.scm.
* scripts/mescc.in: Update from scripts/mescc.
* build-aux/pre-inst-env.in: New file.
* build-aux/cc-mes.sh: Use pre-inst-env.
* configure: Substitute new .in files.
* install.sh: Do not substitute mescc, boot-0.scm.
Jan Nieuwenhuizen