MAINT-7168 Avatar rendering settings adjustments

indra/newview/CMakeLists.txt

indra/newview/app_settings/settings.xml

indra/newview/llfloateravatarrendersettings.cpp

indra/newview/llfloateravatarrendersettings.h

indra/newview/llfloaterpreference.cpp

indra/newview/llfloaterpreference.h

indra/newview/llmutelist.cpp

indra/newview/llmutelist.h

indra/newview/llstartup.cpp

indra/newview/llviewerfloaterreg.cpp

indra/newview/llvoavatar.cpp

indra/newview/llvoavatar.h

...w/skins/default/xui/en/floater_avatar_render_settings.xml

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

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

...w/skins/default/xui/en/menu_avatar_rendering_settings.xml

...view/skins/default/xui/en/panel_preferences_graphics1.xml