Use correct size key backgrounds to avoid scaling.

Also increase padding at the bottom of the keyboard, below the spacebar.
diff --git a/res/layout/input.xml b/res/layout/input.xml
index c4bcc91..f2f30ca 100755
--- a/res/layout/input.xml
+++ b/res/layout/input.xml
@@ -24,4 +24,6 @@
         android:layout_alignParentBottom="true"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
+        android:background="@drawable/keyboard_background"
+        android:keyBackground="@drawable/btn_keyboard_key"
         />