First pass at new FolderIcon visual treatment

-> Modeled as a set of items around a circle
-> Modulate the radius and icon size as number of items grow
-> Clip the icons by a circular clip aligned to the background drawable

Remaining issues
-> Probably want to move to a programmaticly drawn circle + shadow
-> Anti-aliasing of the clipped region will need more attention
-> Need to animate all items in the preview as it changes (this
   wasn't required before)

Change-Id: I678ec605f6c8a34e9d7e4aec4e9583e36a9ef394

src/com/android/launcher3/FastBitmapDrawable.java

@@ -93,7 +93,7 @@ public class FastBitmapDrawable extends Drawable {
     private static final ColorMatrix sTempBrightnessMatrix = new ColorMatrix();
     private static final ColorMatrix sTempFilterMatrix = new ColorMatrix();
 
-    private final Paint mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
+    private final Paint mPaint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.ANTI_ALIAS_FLAG);
     private final Bitmap mBitmap;
     private State mState = State.NORMAL;