Determines the number of hit points someone currently has.
The object whose hitpoints we are to retrieve. (Default: OBJECT_SELF)
Returns the number of hitpoints oObject has and 0 if oObject is invalid.
This can be called upon any object with hit points - Doors, Placeables and so on therefore have values for this.
It can also be negative, if dying or dead.
author: Tom Cassiotis, editor: Jasperre, additional contributor(s): Jasperre