v2.0-dev

New organization : create new hierarchical package name and reorder
Add new fields in item classes
Add new type enums
Add sample of item.json database
Add full javadoc into Item classes
TODO :
- Sorting and constriction of json item database, keep one element of
each type
- Check Items with json item database
- Check Enums with json item database
- Check Components with json item database
- Add javadoc into Enums and Component
- Find out other classes in GW2API packages and implement them