The AES modes OFB and CFB are defined with 128 feedback bits. This

The AES modes OFB and CFB are defined with 128 feedback bits.  This
deviates from the "standard" 64 bits of feedback that all other
algorithms are using.  Therefore, let's redo certain EVP macros to
accept different amounts of feedback bits for these modes.

Also, change e_aes.c to provide all usually available modes for AES.
CTR isn't included yet.