Copying the themes directory in grub-shell isn't
parallel-test-friendly and breaks on the second test when the source
directory is read-only (as in "make distcheck"). Instead, add a
hidden --themes-directory option to grub-mkrescue et al, and use it
in grub-shell.
* include/grub/util/install.h (GRUB_INSTALL_OPTIONS): Add
--locale-directory option.
(enum grub_install_options): Add
GRUB_INSTALL_OPTIONS_LOCALE_DIRECTORY.
* util/grub-install-common.c (grub_install_help_filter): Handle
GRUB_INSTALL_OPTIONS_LOCALE_DIRECTORY.
(grub_install_parse): Likewise.
(get_localedir): New function to check for a user-provided option
before trying grub_util_get_localedir.
(copy_locales): Use get_localedir rather than
grub_util_get_localedir. Handle differing locale directory layouts.
(grub_install_copy_files): Likewise.
the function of these files exceeds what can be sanely handled in shell
in posix-comaptible way. Also writing it in C extends the functionality
to non-UNIX-like OS and minimal environments.
