Merged in chui beta code.

indra/llui/lltabcontainer.cpp

indra/newview/llchathistory.cpp

indra/newview/llfloaterimcontainer.cpp

indra/newview/llfloaterimcontainer.h

indra/newview/llfloaterimnearbychat.cpp

indra/newview/llfloaterimsession.cpp

indra/newview/llfloaterimsession.h

indra/newview/llimview.cpp

indra/newview/llviewermenu.cpp

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

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

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