[RLVa] f9f8dbe23ec3 ported

- internal : reviewed @startim for CHUI (SL-3.5)
    -> fixed : "Start Conference Chat" on a selection of multiple calling cards opens an IM session
    -> fixed : actions that would result in an IM window opening shouldn't be blocked if the session is already open
    -> added : RlvActions class to mimick LLAvatarActions and lowering the rlvhandler.h include dependency

indra/newview/CMakeLists.txt

@@ -574,6 +574,7 @@ set(viewer_SOURCE_FILES
     noise.cpp
     pipeline.cpp
     qtoolalign.cpp
+    rlvactions.cpp
     rlvcommon.cpp
     rlvextensions.cpp
     rlvfloaterbehaviour.cpp
@@ -1100,6 +1101,7 @@ set(viewer_HEADER_FILES
     noise.h
     pipeline.h
     qtoolalign.h
+    rlvactions.h
     rlvcommon.h
     rlvdefines.h
     rlvextensions.h