[code review only] Extract faceted perlin generator to core 

Known issues:
- still no trees
- havent tested multiplayer
- fog/humidity/temperature not functioning

Questions:
- Are you against enabling other sorts of generators? By fitting facets into the previous systems it doesn't restrict the implementation (as apposed to the opposite where we could force facet use).
- Originally I attempted to take all the facet stuff and plunk it in a separate module.  However,  this causes problems because the use of annotations in a module is forbidden.  Do you figure having it in the engine is an ok place?  Alternatively, one could make it not annotation driven to make it compatible with module security (using a produces() and requires() methods on the instantiated class),  but then we lose the understandability of the lifecycle of these classes that annotations do so well.


I suspect oceans shouldn't necessarily go to near the "bottom" of the world, although certainly deeper than lakes. Consider sub-ocean content options like a deeper magma sea, caves, whole layers of additional stuff, planets with realistic interiors, etc :-)

(this might be an obvious comment already, but just in case)