Print all libcurl calls if -DDEBUG_CURLIO. Don't create static lib for cwdebug.

Basically, cmake doesn't support linking static libs into a shared lib.
The correct way is to just specify source files in subdirectories
directly as source files of the shared library. This patch changes that.

Also, after this commit, when DEBUG_CURLIO is defined, every call to
libcurl is printed to llinfos (or to dc::curl when using libcwd).

indra/llmessage/llproxy.cpp

@@ -29,7 +29,6 @@
 #include "llproxy.h"
 
 #include <string>
-#include <curl/curl.h>
 
 #include "llapr.h"
 #include "llcurl.h"