Apply program name transformations at build-time rather than at

Apply program name transformations at build-time rather than at
run-time.  Fixes Debian bug #696465.

* acinclude.m4 (grub_TRANSFORM): New macro.
* configure.ac: Create output variables with transformed names for
most programs.
* util/bash-completion.d/grub-completion.bash.in: Use
pre-transformed variables for program names.
* util/grub-install.in: Likewise.
* util/grub-kbdcomp.in: Likewise.
* util/grub-mkconfig.in: Likewise.
* util/grub-mkconfig_lib.in: Likewise.
* util/grub-mknetdir.in: Likewise.
* util/grub-mkrescue.in: Likewise.
* util/grub-mkstandalone.in: Likewise.
* util/grub-reboot.in: Likewise.
* util/grub-set-default.in: Likewise.
* util/powerpc/ieee1275/grub-mkrescue.in: Likewise.
* tests/util/grub-shell-tester.in: Remove unused assignment.
* tests/util/grub-shell.in: Likewise.
* util/grub.d/00_header.in: Likewise.