Fix #1657 by allowing any request URI, but disabling static file serving outside of known directories
Use Public folder to hold files for the root
Added Error page to Public folder and updated custom error urls as necessary
Added some web.config comments to clarify things
Merge pull request #1672 from NuGet/anurse/1657-requestfiltering

Fix #1657 by allowing any request URI, but disabling static file serving...