Reintroduce stripped license of AES code

[pandame]

The source code in ref/haraka.c notes that parts were taken from @pornin's BearSSL code. The relevant code is licensed under the MIT license.

The MIT license requires that the whole license notice including the copyright lines be present in all copies ("The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software", see also Kyle Mitchell's excellent write-up] "The MIT License, Line by Line" on the MIT license).

There are entire sections that are just 1:1 copies with maybe changed variable names, even ignoring the S-box proper, such as the SWAPN macros and the interleave functions.