Converted ShatteredPD to Build from Gradle

Major Changes:
- Shattered now builds effortlessly either from gradle CLI or android studio
- Much better dependency management through gradle (although it's not really used atm)
- Separate PD-classes repo is now SPD-classes module within main repo

SPD-classes/src/main/java/com/watabou/utils/BitmapCache.java

@@ -0,0 +1,125 @@
+/*
+ * Pixel Dungeon
+ * Copyright (C) 2012-2015  Oleg Dolya
+ *
+ * Shattered Pixel Dungeon
+ * Copyright (C) 2014-2016 Evan Debenham
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package com.watabou.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+
+public class BitmapCache {
+
+	private static final String DEFAULT	= "__default";
+	
+	private static HashMap<String,Layer> layers = new HashMap<String, BitmapCache.Layer>();
+	
+	private static BitmapFactory.Options opts = new BitmapFactory.Options();
+	static {
+		opts.inDither = false;
+	}
+	
+	public static Context context;
+	
+	public static Bitmap get( String assetName ) {
+		return get( DEFAULT, assetName );
+	}
+	
+	public static Bitmap get( String layerName, String assetName ) {
+		
+		Layer layer;
+		if (!layers.containsKey( layerName )) {
+			layer = new Layer();
+			layers.put( layerName, layer );
+		} else {
+			layer = layers.get( layerName );
+		}
+		
+		if (layer.containsKey( assetName )) {
+			return layer.get( assetName );
+		} else {
+			
+			try {
+				InputStream stream = context.getResources().getAssets().open( assetName );
+				Bitmap bmp = BitmapFactory.decodeStream( stream, null, opts );
+				layer.put( assetName, bmp );
+				return bmp;
+			} catch (IOException e) {
+				return null;
+			}
+			
+		}
+	}
+	
+	public static Bitmap get( int resID ) {
+		return get( DEFAULT, resID );
+	}
+	
+	public static Bitmap get( String layerName, int resID ) {
+		
+		Layer layer;
+		if (!layers.containsKey( layerName )) {
+			layer = new Layer();
+			layers.put( layerName, layer );
+		} else {
+			layer = layers.get( layerName );
+		}
+		
+		if (layer.containsKey( resID )) {
+			return layer.get( resID );
+		} else {
+			
+			Bitmap bmp = BitmapFactory.decodeResource( context.getResources(), resID );
+			layer.put( resID, bmp );
+			return bmp;
+			
+		}
+	}
+	
+	public static void clear( String layerName ) {
+		if (layers.containsKey( layerName )) {
+			layers.get( layerName ).clear();
+			layers.remove( layerName );
+		}
+	}
+	
+	public static void clear() {
+		for (Layer layer:layers.values()) {
+			layer.clear();
+		}
+		layers.clear();
+	}
+	
+	@SuppressWarnings("serial")
+	private static class Layer extends HashMap<Object,Bitmap> {
+		
+		@Override
+		public void clear() {
+			for (Bitmap bmp:values()) {
+				bmp.recycle();
+			}
+			super.clear();
+		}
+	}
+}