Add instrumentation, with performance profiling capability (#4132)

* Implement instrumentation for performance profiling

* Add profiling to runtime functions declared in `decl_module` inc.
`on_initialize` and `on_finalize`

* Remove changes

* add docs, tidy up

* fix versions

* fix copyright date

* switch to hashmap and instant

* update example

* update example

* implement receiver for logger and make default

* fix comment

* use `if_std!` macro

* remove whitespace

* fix whitespace

* fix nits

substrate/client/service/test/src/lib.rs

@@ -198,6 +198,8 @@ fn node_config<G, E: Clone> (
 		force_authoring: false,
 		disable_grandpa: false,
 		dev_key_seed: key_seed,
+		tracing_targets: None,
+		tracing_receiver: Default::default(),
 	}
 }