Stop exposing global gssapi symbols.
Rename gss_context_id_t and gss_cred_id_t to local names.
Remove SPNEGO code, its now in its own gssapi module.
Add mechglue inquire functions.
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@17697 ec53bebd-3082-4978-b11e-865c3cabbd6b