Version 0.9

• Removed the grumpyrest-jetty-launcher subproject. This project contained only two helper classes that at best helped
  start a project with Grumpyrest, but had to be replaced later anyway to allow changes. Such code is better located
  in a demo, so I moved these two classes into the grumpyrest-demo subproject.
• added a HOWTO on overriding type converters
• split grumpyjson-gson out of grumpyjson and renamed the latter to grumpyjson-core.
  • moved the dependency on Gson to grumpyjson-gson
  • grumpyjson-core and grumpyrest are no longer depending on Gson
• renamed the base Java package to io.github.grumpystuff to match the group ID
• fix documentation, wiki sync and javadoc sync for the new GitHub namespace