Portals and others

+ End and nether portals with configurability
+ Bed homes
+ Cauldrons fill
+ Added time and weather saving
* ~~Fixes #1066~~
* Fixes #1012, fixes #1194

Portals don't construct/search for a destination portal yet.
Well, I thought giving an optional world would be more performant - if one already has a world pointer (as is the case in DetectPortal()), MoveToWorld() needn't consult cRoot to get it again.

The send respawn is for inter-dimensional travel using actual portals. We want to send the client a respawn packet before the server starts generating/loading chunks (else the client is still playing but can't interact with the world). However, when teleportation is plugin induced, MoveToWorld() should send a respawn. Unless the plugin wants to generate a world too, in which case they may do so.

I'll add this as a comment :P