Clean up dangling references to grub-setup.

Fixes Ubuntu bug #1082045.

* docs/grub.texi (Images): Refer generally to grub-install rather
than directly to grub-setup.
(Installing GRUB using grub-install): Remove direct reference to
grub-setup.
(Device map) Likewise.
(Invoking grub-install): Likewise.
* docs/man/grub-install.h2m (SEE ALSO): Likewise.
* docs/man/grub-mkimage.h2m (SEE ALSO): Likewise.
* util/grub-install.in (usage): Likewise.

* util/bash-completion.d/grub-completion.bash.in (_grub_setup):
Apply to grub-bios-setup and grub-sparc64-setup rather than to
grub-setup.
* configure.ac: Remove grub_setup output variable.

* docs/man/grub-bios-setup.h2m (NAME): Change name from grub-setup
to grub-bios-setup.
* docs/man/grub-sparc64-setup.h2m (NAME): Change name from
grub-setup to grub-sparc64-setup.

docs/man/grub-install.h2m

@@ -3,5 +3,4 @@ grub-install \- install GRUB to a device
 [SEE ALSO]
 .BR grub-mkconfig (8),
 .BR grub-mkimage (1),
-.BR grub-setup (8),
 .BR grub-mkrescue (1)