Pending acl api

I don't know if it matters for this query but in general for large sets of data it's quicker in python to add to a list and then turn it into a string at the end (because strings are immutable in python so 'string1' + 'string2' has to allocate a new string and then copy the contents into it.

That could look something like this:

"""python
else:
    output = ["# Number of requests pending: %s" % len(pending_acls)]
    for entry in sorted(pending_acls, key=lanbda it: it['package']):
        output.append("%(package)s:%(collection)s has %(user)s waiting"\
                " for %(acl)s" % (entry)
    output_str = '\n'.join(output)
"""