Updated to remove most of the warnings in Visual Studio. (There's still the one about all control paths returning a value left.) Fixed one warning (when an istream converts to void * to then convert to bool), and disabled three.

include/conversion.h

@@ -23,7 +23,8 @@ namespace YAML
 	inline bool Convert(const std::string& input, T& output, typename enable_if<is_numeric<T> >::type * = 0) {
 		std::stringstream stream(input);
 		stream.unsetf(std::ios::dec);
-		return stream >> output;
+		stream >> output;
+		return !!stream;
 	}
 }