Merge pull request #15 from MadeInChina/master

Refactor  to maven project(Include android project).
Updated .gitignore to exclude IntelliJ files
Merge branch 'master' of github.com:ripple/ripple-lib-java
Add missing core README.md. Update TypeTranslator interface docs
Use 20090211 org.json json artifact
Update MakePayment with clearer usage instructions
Add ability to send non native amounts using build_path
telLOCAL_ERROR doesn't have a final disposition, keep an eye on transaction stream