Clients can now start their annotation script with anything rather than just 'it' or '_()'

Slight modification to https://github.com/tinkerpop/frames/issues/26

This means that they start a query at parameter or declare a collection for use in the gremlin except retain pattern:

```java
    @GremlinGroovy("person.asVertex().in('knows')")
    public Iterable<Person> getKnownRootedFromParam(@GremlinParam("person") Person person);
```
I've not updated the changelog as I believe this is part of 'Deprecated the use of @_()@ in favor of @it@ in @@GremlinGroovy@'