schannel: Removed curl_ prefix from source files

Removed the curl_ prefix from the schannel source files as discussed
with Marc and Daniel at FOSDEM.

lib/Makefile.inc

@@ -22,11 +22,11 @@
 
 LIB_VTLS_CFILES = vtls/openssl.c vtls/gtls.c vtls/vtls.c vtls/nss.c     \
   vtls/polarssl.c vtls/polarssl_threadlock.c vtls/axtls.c               \
-  vtls/cyassl.c vtls/curl_schannel.c vtls/curl_darwinssl.c vtls/gskit.c
+  vtls/cyassl.c vtls/schannel.c vtls/curl_darwinssl.c vtls/gskit.c
 
 LIB_VTLS_HFILES = vtls/openssl.h vtls/vtls.h vtls/gtls.h                \
   vtls/nssg.h vtls/polarssl.h vtls/polarssl_threadlock.h vtls/axtls.h   \
-  vtls/cyassl.h vtls/curl_schannel.h vtls/curl_darwinssl.h vtls/gskit.h
+  vtls/cyassl.h vtls/schannel.h vtls/curl_darwinssl.h vtls/gskit.h
 
 LIB_CFILES = file.c timeval.c base64.c hostip.c progress.c formdata.c   \
   cookie.c http.c sendf.c ftp.c url.c dict.c if2ip.c speedcheck.c       \

lib/Makefile.vc6

@@ -550,7 +550,6 @@ X_OBJS= \
 	$(DIROBJ)\curl_sasl.obj \
 	$(DIROBJ)\curl_sasl_gssapi.obj \
 	$(DIROBJ)\curl_sasl_sspi.obj \
-	$(DIROBJ)\curl_schannel.obj \
 	$(DIROBJ)\curl_sspi.obj \
 	$(DIROBJ)\curl_threads.obj \
 	$(DIROBJ)\cyassl.obj \
@@ -608,6 +607,7 @@ X_OBJS= \
 	$(DIROBJ)\progress.obj \
 	$(DIROBJ)\rawstr.obj \
 	$(DIROBJ)\rtsp.obj \
+	$(DIROBJ)\schannel.obj \
 	$(DIROBJ)\security.obj \
 	$(DIROBJ)\select.obj \
 	$(DIROBJ)\sendf.obj \

lib/vtls/schannel.c

@@ -47,7 +47,7 @@
 #endif
 
 #include "curl_sspi.h"
-#include "curl_schannel.h"
+#include "schannel.h"
 #include "vtls.h"
 #include "sendf.h"
 #include "connect.h" /* for the connect timeout */

lib/vtls/vtls.h

@@ -30,7 +30,7 @@
 #include "polarssl.h"       /* PolarSSL versions */
 #include "axtls.h"          /* axTLS versions */
 #include "cyassl.h"         /* CyaSSL versions */
-#include "curl_schannel.h"  /* Schannel SSPI version */
+#include "schannel.h"       /* Schannel SSPI version */
 #include "curl_darwinssl.h" /* SecureTransport (Darwin) version */
 
 #ifndef MAX_PINNED_PUBKEY_SIZE