Refactored debug() and log() in CDev

These functions used vprintf which is not available on all platforms.
They also do not enable line and file debug output.

Changed to macros that preserve the output format.  Uses new macro that
can be used to implement per object, runtime selectable logging

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

src/modules/uavcan/uavcan_main.cpp

@@ -489,7 +489,7 @@ int UavcanNode::run()
 
 		// this would be bad...
 		if (poll_ret < 0) {
-			log("poll error %d", errno);
+			DEVICE_LOG("poll error %d", errno);
 			continue;
 
 		} else {