Fix build with old Windows Platform SDK (issue #100)
Fix build with old Windows Platform SDK (issue #100)

* auth/auth_kerb_sspi.c
  (SEC_E_MUTUAL_AUTH_FAILED): Define if not defined.

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