made mIsFocusRoot a XUI param

indra/llui/llpanel.cpp

indra/llui/llview.cpp

indra/llui/llview.h

indra/newview/llnavigationbar.cpp

indra/newview/llpanellogin.cpp

indra/newview/llsidetray.cpp

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

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

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

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

indra/newview/skins/default/xui/en/widgets/sidetray_tab.xml