node/php/dotnet: figure out what to do about baseLogUrl

[domharrington]

Do we still want to accept it? Is this something that we should be doing for them, or encouraging it via the code samples instead?

[gratcliff]

I'm in favor of dropping configuration support for this. We should implicitly be getting this value via the call to ReadMe's dash API.

This will require us to consume that endpoint's response more holistically and apply it to request contexts, though.