Cache resolved SPN for SSPI-based Negotiate authentication.
Cache resolved SPN for SSPI-based Negotiate authentication.

* auth/auth_spnego_sspi.c
  (serf__spnego_context_t): Add POOL and TARGET_NAME.
  (serf__spnego_create_sec_context): Initialize POOL and TARGET_NAME.
  (serf__spnego_init_sec_context): Initialize ctx->TARGET_NAME if not 
   initialized and use it if already it known.

pengdu/serf,google-code-export/serf,lazysoez/serf,SirJson/serf,yesoce/serf,google-code-export/serf,alex1818/serf,lazysoez/serf,x-clone/serf,alex1818/serf,stoneCC/serf,KyleSanderson/serf,SirJson/serf,alex1818/serf,pengdu/serf,zhengcq315/serf,soufianeEL/serf,lazysoez/serf,soufianeEL/serf,zhupan/serf,SirJson/serf,lazysoez/serf,zhupan/serf,zhupan/serf,soufianeEL/serf,pengdu/serf,yesoce/serf,x-clone/serf,zhengcq315/serf,yesoce/serf,alex1818/serf,google-code-export/serf,stoneCC/serf,google-code-export/serf,stoneCC/serf,x-clone/serf,stoneCC/serf,pengdu/serf,zhengcq315/serf,zhupan/serf,KyleSanderson/serf,yesoce/serf,SirJson/serf,x-clone/serf,KyleSanderson/serf,KyleSanderson/serf,zhengcq315/serf,soufianeEL/serf