Adding better logging for validation. Also adding input name for all

logging.

Will this get the name of the class which is inheriting from `ModularInput`? If so, this could be something totally useless like `Program` ([look at the github example](https://github.com/splunk/splunk-sdk-csharp-pcl/blob/master/examples/github-commits/Program.cs#L14))

Also, 5 minutes of updating modinput unit tests for these log statements would be great