Update .scr keyword list.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
Add 'type' keyword.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
M-x cryptol-backends

Signed-off-by: Austin Seipp <aseipp@pobox.com>
Add 'include' keyword.

Signed-off-by: Austin Seipp <aseipp@pobox.com>