Added graphics preference setting for physics.

indra/newview/app_settings/high_graphics.xml

indra/newview/app_settings/low_graphics.xml

indra/newview/app_settings/mid_graphics.xml

indra/newview/app_settings/settings.xml

indra/newview/app_settings/ultra_graphics.xml

indra/newview/llappviewer.cpp

indra/newview/llbreastmotion.cpp

indra/newview/llbreastmotion.h

indra/newview/llfloaterpreference.cpp

indra/newview/llviewercontrol.cpp

indra/newview/llvoavatar.cpp

indra/newview/llvoavatar.h

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