Update RFC number
Update to include pointers to relevant PRs

Update per suggestions from @bosilca - include an attribute by which a
caller can name the allocation request, and a new query attribute by
which a caller can request the status of that request

Update the example - root process needs to set the allocation request
name

Add "cancel" attribute to cancel allocation request in the queue

Add event notification support and further detail on how other processes
can determine allocation request status

Correct spelling

Add description of server-side callback function

Update name of allocation complete event per Josh Hursey suggestion

Signed-off-by: Ralph Castain <rhc@open-mpi.org>