Include timestamp of commit in logging

Turns out that git clean can actually delete files with paths that are "too long." The trick is to enable the support with git config core.longpaths true. This means we can remove the hacky workaround of robocopying an empty directory and re-cloning the repo every time.

* Acquire benchview tools using nuget

* Make timestamp match RFC 3339, Section 5.6. Initial try at calling benchview scripts

* Upload xunit performance results to benchview

* Format calls to benchview tools more nicely

* Change email to use benchview alias

* Name submission json using commit hash to prevent conflicts in blob storage

* Change owner, update config