schannel: Added definitions which are missing in mingw32

#define UNISP_NAME_A "Microsoft Unified Security Protocol Provider"

#endif

#ifndef UNISP_NAME_W

#define UNISP_NAME_W L"Microsoft Unified Security Protocol Provider"

#endif

#ifndef UNISP_NAME

#ifdef UNICODE

#define UNISP_NAME  UNISP_NAME_W

#else

#define UNISP_NAME  UNISP_NAME_A

#endif

#endif

#ifndef SP_PROT_SSL2_CLIENT

#define SP_PROT_SSL2_CLIENT             0x00000008

#endif

#ifndef SP_PROT_SSL3_CLIENT

#define SP_PROT_SSL3_CLIENT             0x00000008

#endif

#ifndef SP_PROT_TLS1_CLIENT

#define SP_PROT_TLS1_CLIENT             0x00000080

#endif

#ifndef SP_PROT_TLS1_0_CLIENT

#define SP_PROT_TLS1_0_CLIENT           SP_PROT_TLS1_CLIENT

#endif

#ifndef SP_PROT_TLS1_1_CLIENT

#define SP_PROT_TLS1_1_CLIENT           0x00000200

#endif

#ifndef SP_PROT_TLS1_2_CLIENT

#define SP_PROT_TLS1_2_CLIENT           0x00000800

#endif

#ifndef SECBUFFER_ALERT

#define SECBUFFER_ALERT                 17

#endif

#ifndef ISC_RET_REPLAY_DETECT

#define ISC_RET_REPLAY_DETECT           0x00000004

#endif

#ifndef ISC_RET_SEQUENCE_DETECT

#define ISC_RET_SEQUENCE_DETECT         0x00000008

#endif

#ifndef ISC_RET_CONFIDENTIALITY

#define ISC_RET_CONFIDENTIALITY         0x00000010

#endif

#ifndef ISC_RET_ALLOCATED_MEMORY

#define ISC_RET_ALLOCATED_MEMORY        0x00000100

#endif

#ifndef ISC_RET_STREAM

#define ISC_RET_STREAM                  0x00008000

#endif

CURLcode Curl_schannel_connect(struct connectdata *conn, int sockindex);