Special Orange request; support for SoftBody Goal weights for Lattices.

Animating detailed clothes with softbody becomes messy, so now we'll
try it this way. :)

It simply uses the W (weight) value, as already available in each Lattice
Point. Only had to make it editable;

- NKey panel
- or press W in editmode

Further there's a minimalistic W button in the softbody Panel!

source/blender/src/editobject.c

@@ -2158,6 +2158,19 @@ void special_editmenu(void)
 		else if(nr==2)
 			armature_flip_names();
 	}
+	else if(G.obedit->type==OB_LATTICE) {
+		static float weight= 1.0f;
+		if(fbutton(&weight, 0.0f, 1.0f, 10, 10, "Set Weight")) {
+			int a= editLatt->pntsu*editLatt->pntsv*editLatt->pntsw;
+			BPoint *bp= editLatt->def;
+			
+			while(a--) {
+				if(bp->f1 & SELECT)
+					bp->vec[3]= weight;
+				bp++;
+			}	
+		}
+	}
 
 	countall();
 	allqueue(REDRAWVIEW3D, 0);