Add telemetry collection code to Winjs to be used in Microsoft WinJS fra...

...mework package.

2 files are added:
1. _telemetryImpl.js - which will be used when building Microsoft WinJS framework package
2. _telemetry.js - the default no-op file
We should capitalize `_telemetry` since it will have methods hanging off of it. That way we can refer to it like this: `WinJS.Utilities._Telemetry`. This will make it consistent with things like `WinJS.Utilities.Scheduler` and `WinJS.Class`.