Fixed major bug EXT-6602 (Sidebar panel focus goes to filter field, obscuring watermark text).

-Set focus on sidetray tabs open to tab containers which hold panels with lists, so now filter fields are not emptied. Used "default_tab_group" + "tab_group" attributes in xml to implement this.

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/198/

--HG--
branch : product-engine

indra/newview/skins/default/xui/en/panel_main_inventory.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <panel
  background_visible="true"
+ default_tab_group="1"
  follows="all"
  height="408"
  label="Things"
@@ -61,6 +62,7 @@
      left="7"
      name="inventory filter tabs"
      tab_height="30"
+     tab_group="1"
      tab_position="top"
      tab_min_width="100"
      top_pad="10"

indra/newview/skins/default/xui/en/panel_people.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <!-- Side tray panel -->
 <panel
+ default_tab_group="1"
  follows="all"
  height="449"
  label="People"
@@ -56,6 +57,7 @@
      layout="topleft"
      left="5"
      name="tabs"
+     tab_group="1"
      tab_min_width="70"
      tab_height="30"
      tab_position="top"

indra/newview/skins/default/xui/en/panel_places.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <panel
 background_visible="true"
+ default_tab_group="1"
  follows="all"
  height="570"
  label="Places"
@@ -37,6 +38,7 @@ background_visible="true"
      name="Places Tabs"
      tab_min_width="80"
      tab_height="30"
+     tab_group="1"
      tab_position="top"
      top_pad="10"
      width="315" />

indra/newview/skins/default/xui/en/sidepanel_appearance.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <panel
 background_visible="true"
+default_tab_group="1"
 follows="all"
 height="570"
 label="Outfits"
@@ -90,6 +91,7 @@ width="333">
    min_height="410"
    width="320"
    left="0"
+   tab_group="1"
    top_pad="6"
    follows="all" />
   <!--   <button