Change handling of back key

1. quit full screen
2. close drawer
3. close dialogs
4. regular back stack
5. close IITC

dialogs can always be closed via [OK], the drawer still reacts on the left edge

mobile/src/com/cradle/iitc_mobile/IITC_NavigationHelper.java

@@ -223,6 +223,10 @@ public class IITC_NavigationHelper extends ActionBarDrawerToggle implements OnNa
         updateActionBar();
     }
 
+    public void closeDrawer() {
+        mDrawerLayout.closeDrawers();
+    }
+
     public String getPaneTitle(Pane pane)
     {
         switch (pane) {
@@ -243,6 +247,10 @@ public class IITC_NavigationHelper extends ActionBarDrawerToggle implements OnNa
         }
     }
 
+    public boolean isDrawerOpened() {
+        return mDrawerOpened;
+    }
+
     public boolean hideInFullscreen() {
         return mHideInFullscreen;
     }