curl: use WNT native Schannel SSL/TLS implementation

This should give better OS integration for things like adding CAs.

Change-Id: I53fbfad402618e98d4116a0fecf0bf59e905e292

external/curl/UnpackedTarball_curl.mk

@@ -20,6 +20,7 @@ $(eval $(call gb_UnpackedTarball_fix_end_of_line,curl,\
 $(eval $(call gb_UnpackedTarball_add_patches,curl,\
 	external/curl/curl-freebsd.patch.1 \
 	external/curl/curl-msvc.patch.1 \
+	external/curl/curl-msvc-schannel.patch.1 \
 	external/curl/curl-7.26.0_mingw.patch \
 	external/curl/curl-7.26.0_win-proxy.patch \
 ))

external/curl/curl-msvc-schannel.patch.1

+MSVC: use WNT native Schannel SSL/TLS implementation
+
+--- curl/lib/Makefile.vc10.old	2013-11-19 00:00:29.044499752 +0100
++++ curl/lib/Makefile.vc10	2013-11-19 00:01:29.135499684 +0100
+@@ -260,7 +260,7 @@
+ TARGET = $(LIBCURL_DYN_LIB_REL)
+ DIROBJ = $(CFG)
+ LNK    = $(LNKDLL) $(WINLIBS) /out:$(DIROBJ)\$(TARGET) /IMPLIB:$(DIROBJ)\$(LIBCURL_IMP_LIB_REL)
+-CC     = $(CCNODBG) $(RTLIB)
++CC     = $(CCNODBG) $(RTLIB) $(CFLAGSWINSSL)
+ CFGSET = TRUE
+ RESOURCE = $(DIROBJ)\libcurl.res
+ !ENDIF
+@@ -411,7 +411,7 @@
+ TARGET = $(LIBCURL_DYN_LIB_DBG)
+ DIROBJ = $(CFG)
+ LNK    = $(LNKDLL) $(WINLIBS) /DEBUG /out:$(DIROBJ)\$(TARGET) /IMPLIB:$(DIROBJ)\$(LIBCURL_IMP_LIB_DBG) /PDB:$(DIROBJ)\$(LIBCURL_DYN_LIB_PDB)
+-CC     = $(CCDEBUG) $(RTLIBD) 
++CC     = $(CCDEBUG) $(RTLIBD) $(CFLAGSWINSSL)
+ CFGSET = TRUE
+ RESOURCE = $(DIROBJ)\libcurl.res
+ !ENDIF