Replace libcurses with our own vt100 handling for the ease of testing

and decreasing prerequisites.

include/grub/terminfo.h

@@ -82,9 +82,7 @@ grub_err_t EXPORT_FUNC (grub_terminfo_output_register) (struct grub_term_output
 							const char *type);
 grub_err_t EXPORT_FUNC (grub_terminfo_output_unregister) (struct grub_term_output *term);
 
-#ifndef GRUB_MACHINE_EMU
 void grub_terminfo_init (void);
 void grub_terminfo_fini (void);
-#endif
 
 #endif /* ! GRUB_TERMINFO_HEADER */