Started new section in NEWS
Improving error handling.
Added check to add attributes only if data is returned.
Added message with url.
Improving error handling.
Added 'all' option to readNWISpCode function. Returns all pCodes with a new call to the service.
You can now get the full dataset from readNWISpCode function, and it's up-to-date.
Merge pull request #58 from ldecicco-USGS/master

Improving error handling.