GNU-EFI has removed the -S (strip-all) option, so do we.
Implement EFI keyboard functions. Mostly done.
Implemented EFI serial code. Seems to work.

Not sure we can pass EFI drivers to kernel so probably
should remove commented kernel args section later.
Loop on EFI_NOT_READY when checking for keypress.

Not sure
Partial implementation of EFI debug functions.

Lacks implementation of debug_init_post_mmu and debug_cleanup
Update Jamfile and work in progress on start.cpp

Enable serial and early debug functions.