Merge sl-search-opt-in back into the release branch

etc/message.xml

indra/llmessage/llregionflags.h

indra/llprimitive/object_flags.h

indra/newview/llagent.cpp

indra/newview/llagent.h

indra/newview/llfloaterland.cpp

indra/newview/llfloaterland.h

indra/newview/llfloaterregioninfo.cpp

indra/newview/llgroupmgr.cpp

indra/newview/llgroupmgr.h

indra/newview/llpanelavatar.cpp

indra/newview/llpanelgroup.cpp

indra/newview/llpanelgroupgeneral.cpp

indra/newview/llpanelgroupgeneral.h

indra/newview/llpanelpermissions.cpp

indra/newview/llpanelpermissions.h

indra/newview/llselectmgr.cpp

indra/newview/llselectmgr.h

indra/newview/llviewerobject.cpp

indra/newview/llviewerobject.h