Various for loop cleanup, const ref cleanup, and other small maint work

indra/newview/alviewermenu.cpp

indra/newview/llagent.cpp

indra/newview/llagent.h

indra/newview/llagentcamera.cpp

indra/newview/llagentcamera.h

indra/newview/llavatarlist.cpp

indra/newview/llavatarlist.h

indra/newview/llavatarrenderinfoaccountant.cpp

indra/newview/llchatitemscontainerctrl.cpp

indra/newview/llchiclet.cpp

indra/newview/llcompilequeue.cpp

indra/newview/llcontrolavatar.cpp

indra/newview/llconversationmodel.cpp

indra/newview/llconversationview.cpp

indra/newview/lldaycyclemanager.cpp

indra/newview/lldaycyclemanager.h

indra/newview/lleasymessagereader.cpp

indra/newview/lleasymessagereader.h

indra/newview/llenvmanager.h

indra/newview/lleventnotifier.cpp