Added Api Key support on the proxy server (returns 401 unauth if enabled and no "ApiKey" request header)
fixed comment
added config key for proxyApiBaseUrl so it's like the other samples
Added dummy "ApiKey" HTTP header in clients, so it's on by default.
Turned off ApiKey support by default, not everyone will need/use it.
Updated Sample LinqPad scripts to include ApiKey header as well.
Merge pull request #11 from wislon/addApiKeySupport

Add Proxy Api Key support (for tracking specific client/app usage)