Project review: AES-NI support

[Greg Hudson]

I've put together a candidate implementation of AES-NI support in the
libk5crypto builtin AES enc-provider.  Here is the project writeup:

    http://k5wiki.kerberos.org/wiki/Projects/AES-NI_Support

and here is the code (this branch will eventually go away after the code
is merged into master):

    https://github.com/greghudson/krb5/tree/aesni

Comments are appreciated.