Continue the never ending war on string temporaries

indra/llcommon/llstring.cpp

indra/llmessage/llavatarname.cpp

indra/llmessage/llcachename.cpp

indra/llmessage/llexperiencecache.cpp

indra/llmessage/llhttpnode.cpp

indra/llmessage/lltrustedmessageservice.cpp

indra/llui/llfloater.cpp

indra/llui/llnotifications.cpp

indra/newview/llmeshrepository.cpp

indra/newview/llviewerchat.cpp

indra/newview/rlvinventory.cpp