Add support for NTP authentication

[Bernhard Reutner-Fischer]

On 15 October 2018 22:54:17 CEST, Brandon Enochs <enochs.brandon at gmail.com> wrote:
>Here's the hopefully complete patch:

>>
>> Was the memcpy+xstrdup better than the individual stores? Which
>version of
>> gcc did you try?

You didn't answer this. 
Please send git format-patch patches, including a Signed-off-by statement to clarify copyrights.
And please include full bloat-o-meter output (ideally mentioning the compiler, linker, assembler used) for reference.

TIA,