Removed plain sand block and tile; incremented version

To be honest, I kinda forgot to increment version in last commit, so I
decided to make a pointless change to justify an entire commit =\

src/main/java/ru/windcorp/progressia/test/LayerAbout.java

@@ -50,7 +50,7 @@ public class LayerAbout extends GUILayer {
 			new Label(
 				"Version",
 				font,
-				new MutableStringLocalized("LayerAbout.Version").format("pre-alpha 2")
+				new MutableStringLocalized("LayerAbout.Version").format("pre-alpha 3")
 			)
 		);
 

src/main/java/ru/windcorp/progressia/test/TestContent.java

@@ -108,7 +108,6 @@ public class TestContent {
 		registerSimplestBlock("Water");
 		registerSimplestBlock("Brick");
 		registerSimplestBlock("BrickWhite");
-		registerSimplestBlock("Sand");
 		registerSimplestBlock("Concrete");
 		registerSimplestBlock("WoodenPlank");
 		
@@ -195,7 +194,6 @@ public class TestContent {
 		});
 
 		registerSimplestTransparentTile("Stones");
-		registerSimplestTransparentTile("Sand");
 
 		registerSimplestOpaqueTile("SnowOpaque");
 		Arrays.asList(

src/main/java/ru/windcorp/progressia/test/gen/feature/TestGrassFeature.java

@@ -67,7 +67,6 @@ public class TestGrassFeature extends SurfaceTopLayerFeature {
 
 	private final List<TileData> scatter = ImmutableList.of(
 		TileDataRegistry.getInstance().get("Test:Stones"),
-		TileDataRegistry.getInstance().get("Test:Sand"),
 		TileDataRegistry.getInstance().get("Test:Bush"),
 		TileDataRegistry.getInstance().get("Test:Fern")
 	);