[DRAFT][PATCH] Convert fakeauth helper to using libntlmauth

Taking this in baby steps, previous attempts at straightening
NTLM/SMB/SSP code out hit bad tangles. So here is the first section of
part 1 (there is a little more part 1 still to come).

Overall plan:
  * merge the simple operations from fakeauth -> libntlmauth
  * rename libntlmauth -> libntlmssp
  * merge the operations of MSNT/smbval -> libntlmssp
  * merge the operations of smb_lm/libntlmssp -> libntlmssp

As each helper is done its rename and build updates are also done. If
it's too big that may be done as a followup part on the library merger.

This is some/most of the fakeauth merger, so people can look over and
see whats the above involves...

This patch:
  - renames fakeauth to ntlm_fake_auth
  - links ntlm_fake_auth to libntlmauth
  - removes fakeauth/ntlm.h header duplicate code.
  - moves the remaining bits of fakeauth/ntlm.h to ntlm_fake_auth.cc.
  - removes duplicate code provided by libcompat from ntlm_fake_auth.cc
  - moves some of the basic operations into libntlmauth
     * fetch_string UNICODE support
     * make challenge packet operation
     * validate packet type
     * make challenge nonce
  - tweaks libntlmauth to split the make challenge operation so that it
only generates the challenge object (does not encode for sending, or
hard-code flags any more).
  - tweaks the smb_lm helper which already linked libntlmauth so that it
uses the libntlmauth API correctly after the above changes.
  - documents libntlmauth and some of ntlm_fake_auth helper

TODO: migrate simple encode, decode, and make_X packet actions for the
other packet types into libntlmauth

After that TODO is completed the full merge request will be made. This
is just a draft preview for initial audit.

Amos

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