[Feature]: Add support for the SHA-256 auth algorithm

[jwillikers]

Describe the feature request

I'd like to use this on a host that uses SHA-256 for the auth algorithm, but it doesn't look like it's supported.

[martialblog]

@RincewindsHat can you have a look at this?

[martialblog]

Maybe we could extend the auth-proto flag to include a SHA256 option?

@jwillikers Pull Requests are welcome, if you want to implement this

[jwillikers]

Sweet, I'll try to find some time to add that. Should be pretty trivial since it is supported in the net-snmp library.

[RincewindsHat]

Jup, could be done in a way which would not disturb the other options.
If net-snmp supports it, this should be relatively easy.
Testing would be annoying though.

[jwillikers]

Jup, could be done in a way which would not disturb the other options. If net-snmp supports it, this should be relatively easy. Testing would be annoying though.

@RincewindsHat I found your branch and that works for me, although I think I've ran into an unrelated bug which I opened an issue for: #26.

[RincewindsHat]

Good to know, thanks :-)
Wanted to add the help for that option and stuff and didn't find the time since then.

[jwillikers]

I went ahead and updated the documentation and help output for you in #27.