…f some datapoints.

This provides infrastructure for for adding concrete implementations for telemetry logger which will implement ITelemetryFactory.

…do some cleanup e.g. flushing data can do it.

Using $(VSTarget) token instead of hardcoded version numbers in telemetry project file

- renamed DefaultTelemetryLogger and factory to DummyTelemetryLogger ...
- some namespace sorting and tab/space alignment fixes
- made classes for telemetry constants static

- Removed all references to vslogger
- Added some overrides in Dapapointcollection to add items more conviniently
- some minor alignment/typo fixes
- Made Telemetry project anycpu and removed unnecessary items from it. set comvisible false for it
- Extracted code to set some common telemetry properties and logging of packageloaded event to a more common place so that it can be called from any package
- removed logging of project open/create as it is already covered by vs telemetry

using new approach to copy and reference private telemetry dlls
directly.
Updating nuget.exe to latest as that is required by latest stable app
insight nugets

Moved Telemetry events and properties classes to shared project and
marked them internal
Including app insights dlls in Dev11 and 12 only
Updated telemetry dlls
Fixed indentation
some other minor fixes

…ommon

…s folder during build

…ith a parallel PR and avoid conflicts later

…o telemetry