This patch enables preliminary support for the SPNEGO protocol (Microsoft's Negotiate protocol) via the GSSAPI library. This means that only UNIX-like operating systems (including Linux and OSX) are supported. A SSPI-based solution is needed for WIN32. Only HTTP authentication is currently supported. Mail protocols will follow. Patch by: Daniel Kouril <kouril@ics.muni.cz> (original author) Wyllys Ingersoll <wyllys.ingersoll@sun.com> Christopher Nebergall <cneberg@sandia.gov> Darin Fisher <darin@meer.net> r=dougt sr=bryner a=chofmann git-svn-id: svn://10.0.0.236/trunk@153987 18797224-902f-48f8-a5cc-f745e15eee43