Added Euler Direction Interface
Merge branch 'master' of https://github.com/SpongePowered/SpongeAPI
Added a few more methods to EulerDirection, and fixed JavaDocs a bit
Fix Comparable troubles
Merge pull request #180 from kenzierocks/euler-direction-extends-comparable

Fix Comparable troubles
Preliminary work to split Entity into a list of interfaces.

This will make way for the entity component system, and also maximize
reusability because you will be able to work with, for example, just
Feedable objects, whether they are even an Entity or not.
Change Positionable to use doubles rather than floats.
Added base class for custom events
Add a roll component to EulerDirection
Added EulerDirection to Rotatable
Adds event cancelling interface and support
Move the command API to .util.commands.
Add a sevice manager interface and Owner interface.
Add preliminary permission service.
Add preliminary command dispatcher service.
Update Block's ID call and update its Javadocs.
Add Identifiable interface and make Entity use it.
Add Extent as a super interface for World.
Add missing @Override in BaseEvent.
Add causes for events.