Windows and other AEAD ciphers

[James Browning]

Building on windows will cause pain in the neck. Microsoft's SDK coaster image 
is a gigabyte and a half compressed. However, after too much frustration, I 
got an unrelated toy program to build on Linux.

Building NTPsec on Linux but for Windows would require us to either bring back 
or re-implement the code that made it happen before. Windows does not have a 
good Posix environment. I completed the configuration process after turning off 
checks for the following.

- libm
- stdbool.h
- struct timex and two of its members
- EVP_PKEY_new_CMAC_key
- TLS1.3
- OpenSSL version

Anyone up to working on it should look at the git-conversion tag. I am not in 
the weight class to tackle the NT shim.

OTOH, I will eventually be able to get other AEAD algorithms supported by 
NTPsec. I would not hold my breath, however. OpenSSL has some interesting files 
in its test suite.