Add some comments to some tricky to understand functions.

Source/drlg_l2.cpp

@@ -1153,6 +1153,8 @@ BOOL CreateDungeon()
 	return TRUE;
 }
 
+// Draws a random room rectangle, and then subdivides the rest of the passed in rectangle
+// into 4 pieces and recurses.
 void CreateRoom(int nX1, int nY1, int nX2, int nY2, int nRDest, int nHDir, BOOL ForceHW, int nH, int nW)
 {
 	int nAw, nAh, nRw, nRh, nRx1, nRy1, nRx2, nRy2, nHw, nHh, nHx1, nHy1, nHx2, nHy2, nRid;

Source/drlg_l3.cpp

@@ -1020,6 +1020,9 @@ void DRLG_L3River()
 	}
 }
 
+// Flood fills dirt and wall tiles looking for 
+// an area of at most 40 tiles and disconnected from the map edge.
+// If it finds one, converts it to lava tiles and sets lavapool to TRUE.
 void DRLG_L3Pool()
 {
 	int i, j, dunx, duny, totarea, poolchance;