test: coverage for NFS quota RPC

[garlick]

To get test coverage for the NFS quota client, we need a way to exercise the quota client RPC.

One possiblity is to pull down nfs-ganesha in travis and test against its quota server.

[garlick]

The new rquota_test_svc and rquota_test_clnt executables might be used to put something together.

At the moment, one has to start portmap/rpcbind, and then the svc registers itself. It would conflict with the real quota service if the test system is running a Linux NFS server. If there were a way to skip portmap and start on a specific port, and then tell the client ot use that port, that would be nice.

Starting up ganesha just for a test might be overkill.