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/glwrap/Framebuffer.java

@@ -0,0 +1,69 @@
+/*
+ * 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.glwrap;
+
+import android.opengl.GLES20;
+
+public class Framebuffer {
+
+	public static final int COLOR	= GLES20.GL_COLOR_ATTACHMENT0;
+	public static final int DEPTH	= GLES20.GL_DEPTH_ATTACHMENT;
+	public static final int STENCIL	= GLES20.GL_STENCIL_ATTACHMENT;
+	
+	public static final Framebuffer	system	= new Framebuffer( 0 );
+	
+	private int id;
+	
+	public Framebuffer() {
+		int[] buffers = new int[1];
+		GLES20.glGenBuffers( 1, buffers, 0 );
+		id = buffers[0];
+	}
+	
+	private Framebuffer( int n ) {
+		
+	}
+	
+	public void bind() {
+		GLES20.glBindFramebuffer( GLES20.GL_FRAMEBUFFER, id );
+	}
+	
+	public void delete() {
+		int[] buffers = {id};
+		GLES20.glDeleteFramebuffers( 1, buffers, 0 );
+	}
+	
+	public void attach( int point, Texture tex ) {
+		bind();
+		GLES20.glFramebufferTexture2D( GLES20.GL_FRAMEBUFFER, point, GLES20.GL_TEXTURE_2D, tex.id, 0 );
+	}
+	
+	public void attach( int point, Renderbuffer buffer ) {
+		bind();
+		GLES20.glFramebufferRenderbuffer( GLES20.GL_RENDERBUFFER, point, GLES20.GL_TEXTURE_2D, buffer.id() );
+	}
+	
+	public boolean status() {
+		bind();
+		return GLES20.glCheckFramebufferStatus( GLES20.GL_FRAMEBUFFER ) == GLES20.GL_FRAMEBUFFER_COMPLETE;
+	}
+}