Implement GSS_SPNEGO Adapter as a gem

[satoryu]

In discussion of #226, GSS_SPENEGO authentication adapter must be implemented as a gem to care users who use this authentication method.

CC: @jch

[satoryu]

@jch @mtodd Could you please assign me to this issue?

[satoryu]

Referring the guide, the gem name will be net-ldap-auth_adapter-gss_spnego. how about this?

[jch]

That gem name is a mouthful, but I think it's clear what it's supposed to me. We can also link to it from the README so it's easier for others to find.

[satoryu]

I could not find the repository of the gem 'ntlm-http' on which gss_spnego depends... ;(

[jch]

Did it get yanked? If the implementation isn't too long, you could find the code and just inline it into your gem.

[tmaher]

@satoryu - it looks like it's on rubygems now: https://rubygems.org/gems/ntlm-http/versions/0.1.1

repo appears to be https://github.com/pyu10055/ntlm-http though it's a couple minor revs ahead of what's on RubyGems (0.1.3.3 vs 0.1.1)

[larskanis]

This issue is solved by the gem net-ldap-gss-spnego, so that this issue can be closed and the provisional file for gss_spnego can be removed from net-ldap gem. See #343