Consolidate to single debug macro, activate using feature

src/lib.rs

@@ -1,8 +1,7 @@
+#[macro_use]
 extern crate wasmer_runtime_core;
 // extern crate wasmer_emscripten;
 
-#[macro_use]
-mod macros;
 #[macro_use]
 pub mod update;
 pub mod webassembly;