Docs in GeoIP2.pm and docs for web service client class
Add docs on languages argument for client constructor
Fix mistake in docs for ua argument
Add docs on how missing data is handled
Add docs for the Model classes
Doc list of valid languages in Client docs
Add some info about our integration with Geonames to the top-level GeoIP2 docs
List the en language code first
Fix capitalization of GeoNames
Add docs for all Record classes
Remove License plugin since we want the license in our repo
Add $NEXT token to Changes
Lots of spelling fixes
Add docs for the Error classes
Add use lines to the SYNOPSIS sections
Fix typo in predicate definitions

I have no idea why this doesn't cause an error in the tests - I only saw it
when the Pod coverage tests threw a warning.
Add 1; to GeoIP2.pm
Add pod coverage & spelling tests