fix navscreen orientation

    handle configuration change in navscreen
    capture actual screen for tabs
    size tabs correctly

Change-Id: I20ff72bdcab13678cdba4c55849bd5ff16cb6568
diff --git a/res/values/dimensions.xml b/res/values/dimensions.xml
index 5b962d8..28b9e8b 100644
--- a/res/values/dimensions.xml
+++ b/res/values/dimensions.xml
@@ -67,4 +67,5 @@
     <dimen name="nav_tab_spacing">8dp</dimen>
     <dimen name="menu_width">240dip</dimen>
     <dimen name="toolbar_height">52dip</dimen>
+    <dimen name="tab_capture_size">480dp</dimen>
 </resources>