Disable fullscreen mode

This mode is annoying to some users and is disabled in most text views.

The keyboard has a fixed sized relative to the height of the screen in
landscape mode. The keyboard can't take more space than expected,
currently.

This might cause problems in the future and might be hidden behind an
option if one is found. Every text views so far seemed to behave fine.

srcs/juloo.keyboard2/Keyboard2.java

@@ -276,6 +276,13 @@ public class Keyboard2 extends InputMethodService
     refreshConfig();
   }
 
+  @Override
+  public boolean onEvaluateFullscreenMode()
+  {
+    /* Entirely disable fullscreen mode. */
+    return false;
+  }
+
   /** Not static */
   public class Receiver implements KeyEventHandler.IReceiver
   {