SiO2 version 1.2.0

Change log:

• Fixed a SimTime initialization problem where the first tpf would be
  huge.
• Fixed an issue where EntityContainer wouldn't support nested parameterized
  types.
• Added GameSystemManager.getStepTime()
• Added GameLoop.getStepTime() that is thread-safe with respect to the game loop
  thread.
• Added SimTime.toSimTime() and SimTime.getFutureTime(duration) to help with
  conversion of seconds to game time.
• Added a standard es.common.Decay component for tracking the 'life' of an
  entity.
• Added a standard sim.common.DecaySystem for automatically destroying entities
  whose Decay time has expired.
• Added GameSystemManager.get(class, failOnMiss) that can optionally throw an
  exception if the system does not exist.
• Added AbstractGameSystem.getSystem(class, failOnMiss) that can optionally
  throw an exception if the system does not exist.
• Added a MessageState that can be used to display fading messages popping up from
  the bottom of the screen.
• Added a basic CommandConsoleState that can be used to allow command entry (can
  automatically feed the MessageState).
• Modified DebugHudState to allow user-supplied VersionedObjects to be displayed
  instead of forcing them to be created through the API.
• Added a CameraState to make it easier to independently set camera parameters like
  FOV, near, and far plane values.
• Modified SimTime to initialize baseTime to current time on the first frame so
  that game time begins counting from the first frame.
• Fixed an NPE in CompositeAppState.addChild() when called after the outer state is
  attached but before it was initialized. See PR #5.
• Added SimTime.getUnlockedTime() which will return a SimTime-translated time
  between frames, ie: not frame locked.
• Set sourceCompatibility to 1.7 and turned on detailed 'unchecked' warnings
• Suppressed 'unchecked' warnings in some methods of EntityContainer, EventBus,
  and DecaySystem where it is known that the operations are safe or safe-ish,
  ie: we know we did it for a reason and don't need to be reminded all the time.
• Increased Zay-ES versions to 1.3.0