Windows PowerShell port

This PR introduces a PowerShell port of the original bash script that can be run on Windows.

To run from a PowerShell console, simply:

	./bin/support-diagnostics.ps1

The script accepts all of the command line arguments that the original bash script accepts.

The output is a zip file instead of a tarball.  I also tried to keep variable names as similar as possible to the original script, as well as the general flow / order of operations in effort to make cross-maintenance a little easier.
Is assigning it to `pwd\filename` any different than just assigning it to `filename` from the beginning? I would expect them to resolve to the same location. The same goes for `$source = $outputDir`.

Feel like this if-statement could be removed. and replaced by:

```powershell
$zipFile = $outputDir+'.zip'
$source = $outputDir
$destination = $zipFile
```