Partial revert of 2010-09-20 changes.

* camellia-set-encrypt-key.c (camellia_set_encrypt_key):
Reintroduce CAMELLIA_F_HALF_INV, for 32-bit machines.
* camellia-crypt-internal.c (CAMELLIA_ROUNDSM): Two variants,
differing in where addition of the key is done.
* x86/camellia-crypt-internal.asm: Moved addition of key.

Rev: nettle/ChangeLog:1.110
Rev: nettle/camellia-crypt-internal.c:1.4
Rev: nettle/camellia-set-encrypt-key.c:1.6