Call and use ConfigureServices if exists

Currently only looks for signatures like this:

public [static] void ConfigureServices(IServiceCollection services, ...)

Will add support for more overloads like one that returns a IServiceProvider next
Not sure why the files in this project have the long header. Since you're here... can you do a follow-up PR in Hosting to clean up the headers to the correct (short) version? (https://github.com/aspnet/Logging/blob/dev/src/Microsoft.Framework.Logging.Interfaces/ILogger.cs#L1-L2)