Added the @list and @stopim IM queries

indra/llcommon/llstring.cpp

indra/llcommon/llstring.h

indra/newview/llviewermessage.cpp

indra/newview/rlvcommon.cpp

indra/newview/rlvcommon.h

indra/newview/rlvdefines.h

indra/newview/rlvfloaters.cpp

indra/newview/rlvfloaters.h

indra/newview/rlvhandler.cpp

indra/newview/rlvhandler.h

indra/newview/rlvhelper.h

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

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