Sign the vsix packages

[andorz]

If this issue is a feature request:

• Describe the scenario and benefits that the feature supports.

the user feals more comfortable that he selected the right extension from the marketplace

• Describe how you're accomplishing the feature today (if possible).

at the moment you see that it is not signed.

• Describe what you'd like the new feature to do.

show that the extension that will be installed belongs to the wix toolset (.NET Foundation)

[robmen]

Thanks for cleanly filling out the template. This is something I'd like to implement so thank you for the issue tracking it.

[robmen]

This was done at least a few releases ago.