extra paranoia: fix 'abs()' warnings by leaving behavior unchanged

- I don't have time for extensive testing of any actual game-behavior
  changes like 'abs()-->fabsf()' would introduce, so we'll leave this
  untouched and fix the warnings by explicit casting instead.
  (... this worked fine so far, so no reason to change it, unless done
  properly.)
- refs #31

src/enemy.c

@@ -312,7 +312,7 @@ CheckIfWayIsFreeOfDroids ( float x1 , float y1 , float x2 , float y2 , int OurLe
   DebugPrintf( 2, "\nint CheckIfWayIsFreeOfDroids (...) : Checking from %d-%d to %d-%d.", (int) x1, (int) y1 , (int) x2, (int) y2 );
   fflush(stdout);
 
-  if ( abs(x1-x2) > abs (y1-y2) ) LargerDistance=fabsf(x1-x2);
+  if ( abs((int)(x1-x2)) > abs ((int)(y1-y2)) ) LargerDistance=fabsf(x1-x2);
   else LargerDistance=fabsf(y1-y2);
 
   Steps=LargerDistance * 4 ;   // We check four times on each map tile...

src/influ.c

@@ -502,7 +502,7 @@ CheckInfluenceWallCollisions (void)
 	{
 	  crashx = TRUE;	/* In X wurde gecrasht */
 	  sign = (SX < 0) ? -1 : 1;
-	  SX = abs (SX);
+	  SX = abs ((int)SX);
 	  NumberOfShifts=0;
 	  while (--SX
 		 && (DruidPassable (lastpos.x + sign * SX, lastpos.y) !=
@@ -518,7 +518,7 @@ CheckInfluenceWallCollisions (void)
 	{
 	  crashy = TRUE;	/* in Y wurde gecrasht */
 	  sign = (SY < 0) ? -1 : 1;
-	  SY = abs (SY);
+	  SY = abs ((int)SY);
 	  NumberOfShifts=0;
 	  while (--SY
 		 && (DruidPassable (lastpos.x, lastpos.y + sign * SY) !=
@@ -727,9 +727,9 @@ CheckInfluenceEnemyCollision (void)
       xdist = Me.pos.x - AllEnemys[i].pos.x;
       ydist = Me.pos.y - AllEnemys[i].pos.y;
 
-      if (abs (xdist) > 1)
+      if (abs ((int)xdist) > 1)
 	continue;
-      if (abs (ydist) > 1)
+      if (abs ((int)ydist) > 1)
 	continue;
 
       dist2 = sqrt( (xdist * xdist) + (ydist * ydist) );

src/map.c

@@ -1315,10 +1315,10 @@ MoveLevelDoors (void)
 		  AllEnemys[j].levelnum != CurLevel->levelnum)
 		continue;
 
-	      xdist = abs (AllEnemys[j].pos.x - doorx);
+	      xdist = abs ((int)(AllEnemys[j].pos.x - doorx));
 	      if (xdist < Block_Rect.w)
 		{
-		  ydist = abs (AllEnemys[j].pos.y - doory);
+		  ydist = abs ((int)(AllEnemys[j].pos.y - doory));
 		  if (ydist < Block_Rect.h)
 		    {
 		      dist2 = xdist * xdist + ydist * ydist;