layers:Enable memory access warning callback

Turning on all of the memory tracking code as there is almost no perf
hit on "smoketest --validate -s" now. Also the warning callback has a
large caveat statement to help developers share suspected issues and
disregard as they see fit.

Author: tobine

layers/vk_layer_config.h

@@ -29,7 +29,7 @@
 extern "C" {
 #endif
 
-//#define ENABLE_MEMORY_ACCESS_CALLBACK
+#define ENABLE_MEMORY_ACCESS_CALLBACK
 
 // Definitions for Debug Actions
 typedef enum VkLayerDbgActionBits {