Move gfxmenu color handling to video, so that gfxterm can use it

too.

* grub-core/gfxmenu/named_colors.c: Move to ...
* grub-core/video/colors.c: ... here.  Rename
grub_gui_get_named_color to grub_video_get_named_color.
* grub-core/gfxmenu/gui_string_util.c (my_isxdigit): Move to ...
* grub-core/video/colors.c (my_isxdigit): ... here.
* grub-core/gfxmenu/gui_string_util.c (parse_hex_color_component):
Move to ...
* grub-core/video/colors.c (parse_hex_color_component): ... here.
* grub-core/gfxmenu/gui_string_util.c (grub_gui_parse_color): Move
to ...
* grub-core/video/colors.c (grub_video_parse_color): ... here.

* include/grub/gui.h (grub_gui_color_t): Move to ...
* include/grub/video.h (grub_video_rgba_color_t): ... here.
* include/grub/gui.h (grub_gui_color_rgb): Move to ...
* include/grub/video.h (grub_video_rgba_color_rgb): ... here.
* include/grub/gui.h (grub_gui_map_color): Move to ...
* include/grub/video.h (grub_video_map_rgba_color): ... here.
* include/grub/gui_string_util.h (grub_gui_get_named_color): Move
to ...
* include/grub/video.h (grub_video_get_named_color): ... here.
* include/grub/gui_string_util.h (grub_gui_parse_color): Move to ...
* include/grub/video.h (grub_video_parse_color): ... here.

* grub-core/Makefile.core.def (kernel) [videoinkernel]: Add
video/colors.c.
(gfxmenu): Remove gfxmenu/named_colors.c.
(video_colors) [videomodules]: New module, containing
video/colors.c.

include/grub/gui_string_util.h

@@ -30,8 +30,4 @@ char *grub_resolve_relative_path (const char *base, const char *path);
 
 char *grub_get_dirname (const char *file_path);
 
-int grub_gui_get_named_color (const char *name, grub_gui_color_t *color);
-
-grub_err_t grub_gui_parse_color (const char *s, grub_gui_color_t *color);
-
 #endif /* GRUB_GUI_STRING_UTIL_HEADER */