Added some code to enable the following functionality:
- objects now have a property where they are burning. It is a kind of state
- sticks can be (a)pplied and when they are, they commence burning
- when an object is burning, flames appear
- burning objects cannot be piled together with objects that are not burning
- an object that is burning will emit light
- in ivandef.h and define.dat added the following to denote in how far an item is burnt:
#define NOT_BURNT 0
#define SLIGHTLY_BURNT 1
#define MODERATELY_BURNT 2
#define HEAVILY_BURNT 3

known bugs include that the second item of an item generated in pairs (f.ex. boot, gauntlet) does not have its burning state set to zero initially. Not a dreadful problem at the moment. It just looks like it is on fire, but does not emit light... funny.