HttpPlatformHandler forwards the path un-escaped, breaks for `?`

[Tratcher]

When HttpPlatformHandler forwards the request path and query, it uses the un-escaped path and the original escaped query. This causes a few issues:

1. Query - If there is an escaped ? (%3F) in the original path it is un-escaped and forwarded. The back-end server (kestrel, weblistener) then interprets this as the query separator, breaking both path and query. There is no workaround.
2. Backslash - %5C is unescaped to \ and then converted to /, confusing routing
3. Double un-escaping - This would be a problem if you sent /%25%34%31, except IIS's request filtering logic blocks %25 by default.

[Tratcher]

FYI @davidfowl @halter73

[Tratcher]

Fixed by the next version of HttpPlatformHandler (v1.3?)

[Tratcher]

This as been fixed in AspNetCoreModule v0.8: #105.