Properly complete context establishment
Properly complete context establishment

On success do not forget to send the last negotiate packet (if any)
to the client within the 200 Reply.

Fixes #21

davisd123/mod_auth_gssapi,devurandom/mod_auth_gssapi,frenche/mod_auth_gssapi,frenche/mod_auth_gssapi,uhd-urz/mod_auth_gssapi,frenche/mod_auth_gssapi,uhd-urz/mod_auth_gssapi,devurandom/mod_auth_gssapi,uhd-urz/mod_auth_gssapi,davisd123/mod_auth_gssapi,frenche/mod_auth_gssapi,davisd123/mod_auth_gssapi,devurandom/mod_auth_gssapi