SL-15297 performance floater UI update #2

indra/llui/llscrolllistcell.cpp

indra/llui/llscrolllistcell.h

indra/newview/llfloaterperformance.cpp

indra/newview/llfloaterpreference.cpp

indra/newview/llfloaterpreference.h

indra/newview/llnamelistctrl.cpp

indra/newview/llviewermenu.cpp

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

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

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

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

...iew/skins/default/xui/en/panel_performance_complexity.xml

...a/newview/skins/default/xui/en/panel_performance_huds.xml

...newview/skins/default/xui/en/panel_performance_nearby.xml

...ew/skins/default/xui/en/panel_performance_preferences.xml

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