Fix WorldBank type provider
Fix tests
Some support for the Http type in portable profile and move it back to original namespace +

Move back StructureInference to design time assembly, leaving only the minimum needed types +
Make sure everything not supposed to be used directly is hidden under FSharp.Data.RuntimeImplementation subnamespace
Regenerate html
WorldBank : use JSON instead of XML, support the portable library version & support for topics
Hide implementation methods (#15) + Consume the sample data directly by default (#12)