This patch:
- bumps up the minimum version of python-nss
- will initialize NSS with nodb if a CSR is loaded and it isn't already
  init'd
- will shutdown NSS if initialized in the RPC subsystem so we use right db
- updated and added a few more tests

Relying more on NSS introduces a bit of a problem. For NSS to work you
need to have initialized a database (either a real one or no_db). But once
you've initialized one and want to use another you have to close down the
first one.  I've added some code to nsslib.py to do just that. This could
potentially have some bad side-effects at some point, it works ok now.

When the netgroup plugin was rebased it ended up using the member
attribute for its memberships and not memberuser/memberhost.

I also fixed this same attribute problem in the tests and tried to beef
them up a little. If nis/schema compat are enabled it will try to compare
the generated triplets with a known-good value.

I have to do some pretty low-level LDAP work to achieve this. Since
we can't read the key using our modlist generator won't work and lots of
tricks would be needed to use the LDAPUpdate object in any case.

I pulled usercertificate out of the global params and put into each
appropriate function because it makes no sense for service-disable.

This also adds a new variable, has_keytab, to service/host_show output.
This flag tells us whether there is a krbprincipalkey.

The problem was trying to operate directly on the ACI itself. I
introduced a new function, _aci_to_kw(), that converts an ACI
into a set of keywords. We can take these keywords, like those passed
in when an ACI is created, to merge in any changes and then re-create the
ACI.

I also switched the ACI tests to be declarative and added a lot more
cases around the modify operation.

Also fix the memberOf attribute for the HBAC services