Merge branch 'tc/curl-vernum-output-broken-in-7.11' into maint

Certain older vintages of cURL give irregular output from
"curl-config --vernum", which confused our build system.

* tc/curl-vernum-output-broken-in-7.11:
  Makefile: handle broken curl version number in version check

Makefile

@@ -1035,13 +1035,13 @@ else
 	REMOTE_CURL_NAMES = $(REMOTE_CURL_PRIMARY) $(REMOTE_CURL_ALIASES)
 	PROGRAM_OBJS += http-fetch.o
 	PROGRAMS += $(REMOTE_CURL_NAMES)
-	curl_check := $(shell (echo 070908; curl-config --vernum) 2>/dev/null | sort -r | sed -ne 2p)
+	curl_check := $(shell (echo 070908; curl-config --vernum | sed -e '/^70[BC]/s/^/0/') 2>/dev/null | sort -r | sed -ne 2p)
 	ifeq "$(curl_check)" "070908"
 		ifndef NO_EXPAT
 			PROGRAM_OBJS += http-push.o
 		endif
 	endif
-	curl_check := $(shell (echo 072200; curl-config --vernum) 2>/dev/null | sort -r | sed -ne 2p)
+	curl_check := $(shell (echo 072200; curl-config --vernum | sed -e '/^70[BC]/s/^/0/') 2>/dev/null | sort -r | sed -ne 2p)
 	ifeq "$(curl_check)" "072200"
 		USE_CURL_FOR_IMAP_SEND = YesPlease
 	endif