better control system; album art loading more efficient;

android/assets/uiskin.atlas

@@ -366,7 +366,7 @@ rect
   rotate: false
   xy: 176, 35
   size: 14, 14
-  split: 4, 4, 4, 4
+  split: 3, 3, 3, 3
   orig: 14, 14
   offset: 0, 0
   index: -1
@@ -374,7 +374,7 @@ rect-down
   rotate: false
   xy: 191, 35
   size: 14, 14
-  split: 4, 4, 4, 4
+  split: 3, 3, 3, 3
   orig: 14, 14
   offset: 0, 0
   index: -1
@@ -382,7 +382,7 @@ rect-disabled
   rotate: false
   xy: 206, 35
   size: 14, 14
-  split: 4, 4, 4, 4
+  split: 3, 3, 3, 3
   orig: 14, 14
   offset: 0, 0
   index: -1