New ScriptTickObject

ScriptTickObject is a ScriptObject that adds callbacks for tick and
frame events.  Use setProcessTicks() to enable or disable the
onInterpolateTick() and onProcessTick() callbacks.  The
callOnAdvanceTime property determines if the onAdvanceTime() callback is
called.
Merge pull request #217 from DavidWyand-GG/ScriptTickObject

New ScriptTickObject