Restructure project for maven

Files moved to standard maven/java locations, skeleton pom.xml
added for building via maven.
Convert to Gson

Removes the json.org JSON parser and converts the client to
use the Gson library.

Gson was chosen as the API is similar to json.org when dealing with
basic JSON objects and it is Apache2 licensed.
Changes examples to use JsonObject

The examples now use the new Gson objects.
Add Apache2 license file
Merge pull request #5 from basho/replace-json-org

Replace json org