Replace the "log" server module fn with a "log2"

[Ralph Castain]

Hello all

The current "log" server module function was defined with a void return. This contrasts with most of the other module functions which characteristically return a pmix_status_t, thereby supporting a return status that indicates if the function is not supported or has been atomically completed.

Add a replacement "log2" function that is identical in signature except for returning a pmix_status_t instead of void. Deprecate the current "log" function.

The PR is available here: https://github.com/pmix/pmix-standard/pull/522

Please feel free to comment and/or vote your preference

Ralph