clean up town generation, remove even skippable blocks from town area

(not border).  Should resolve issues of trees generating inside of the
towns (or rather town not clearing out the trees that were in the
bounds)

src/main/java/net/shadowmage/ancientwarfare/structure/town/TownGeneratorBorders.java

@@ -31,7 +31,7 @@ public static void generateBorders(World world, TownGenerator gen)
     for(int pz = gen.maximalBounds.min.z; pz <= gen.maximalBounds.max.z; pz++)
       {
       step = WorldStructureGenerator.getStepNumber(px, pz, eminx, emaxx, eminz, emaxz);
-      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass));
+      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass), true);
       }
     }  
 
@@ -42,7 +42,7 @@ public static void generateBorders(World world, TownGenerator gen)
     for(int pz = gen.maximalBounds.min.z; pz <= gen.maximalBounds.max.z; pz++)
       {
       step = WorldStructureGenerator.getStepNumber(px, pz, eminx, emaxx, eminz, emaxz);
-      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass));
+      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass), true);
       }
     } 
 
@@ -53,7 +53,7 @@ public static void generateBorders(World world, TownGenerator gen)
     for(int px = gen.maximalBounds.min.x; px <= gen.maximalBounds.max.x; px++)
       {
       step = WorldStructureGenerator.getStepNumber(px, pz, eminx, emaxx, eminz, emaxz);
-      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass));
+      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass), true);
       }
     }
 
@@ -64,7 +64,7 @@ public static void generateBorders(World world, TownGenerator gen)
     for(int px = gen.maximalBounds.min.x; px <= gen.maximalBounds.max.x; px++)
       {
       step = WorldStructureGenerator.getStepNumber(px, pz, eminx, emaxx, eminz, emaxz);
-      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass));
+      handleBorderBlock(world, px, pz, fillBase-step, levelBase+step, getFillBlock(world, px, pz, false, Blocks.dirt), getFillBlock(world, px, pz, true, Blocks.grass), true);
       }
     }  
   }
@@ -80,15 +80,15 @@ public static void levelTownArea(World world, TownGenerator gen)
     {
     for(int z = minZ; z<=maxZ; z++)
       {
-      handleBorderBlock(world, x, z, desiredTopBlockHeight, desiredTopBlockHeight, getFillBlock(world, x, z, false, Blocks.grass), getFillBlock(world, x, z, true, Blocks.grass));
+      handleBorderBlock(world, x, z, desiredTopBlockHeight, desiredTopBlockHeight, getFillBlock(world, x, z, false, Blocks.grass), getFillBlock(world, x, z, true, Blocks.grass), false);
       world.setBlock(x, desiredTopBlockHeight-5, z, Blocks.cobblestone);
       }
     }
   }
 
-private static void handleBorderBlock(World world, int x, int z, int fillLevel, int cutLevel, Block fillBlock, Block topBlock)
+private static void handleBorderBlock(World world, int x, int z, int fillLevel, int cutLevel, Block fillBlock, Block topBlock, boolean skippables)
   {  
-  int y = getTopFilledHeight(world.getChunkFromBlockCoords(x, z), x&15, z&15, true);
+  int y = getTopFilledHeight(world.getChunkFromBlockCoords(x, z), x&15, z&15, skippables);
   if(y >= cutLevel)
     {
     for(int py = world.provider.getActualHeight(); py > cutLevel; py--){world.setBlockToAir(x, py, z);}