Extract a member from the library

Z Data Tools uses the exit to extract a member from the LMS library. Since Z Data Tools uses this mechanism from panels which only allow specification of a library name and member name, the exit must be able to determine a unique member solely from the combination of the library and member names. This requires some default decisions by the exit. For example, an LMS can maintain multiple versions of a member. The exit may need to decide to always choose the most recent version when asked for the member by name.