Example generation of complete object graphs.

This pull request contains an object creator for use by the example JSON code generation - see class `ObjectCreator`.  It is able to create an example object tree from concrete or abstract classes.  I had to add some more dependencies, objenesis and hamcrest for testing, also version 3.2 of the spring-context module which provides CGLIB for creating proxies.

There's also a change to the generator so that it accepts `@RequestParam` annotations without an http method declaration.  Previously that caused the Generator to fall over, now it will output `ALL` as the HTTP method name.