pki-silent puts a copy of the root CA into /root/tmp-ca.p12. Rename this
to /root/cacert.p12.

Fixes #528996

Also get rid of functions get_host_name(), get_realm_name() and
get_domain_name(). They used the old ipapython.config. Instead, use the
variables from api.env. We also change them to bootstrap() and
finalize() correctly.

Additionally, we add the dns_container_exists() function that will be
used in ipa-replica-prepare (next patch).

Let the user, upon installation, set the certificate subject base
for the dogtag CA. Certificate requests will automatically be given
this subject base, regardless of what is in the CSR.

The selfsign plugin does not currently support this dynamic name
re-assignment and will reject any incoming requests that don't
conform to the subject base.

The certificate subject base is stored in cn=ipaconfig but it does
NOT dynamically update the configuration, for dogtag at least. The
file /var/lib/pki-ca/profiles/ca/caIPAserviceCert.cfg would need to
be updated and pki-cad restarted.

The parser.error() method prepends the "error: " prefix itself. Adding
it to the error string is not necessary and doesn't look good.

External CA signing is a 2-step process. You first have to run the IPA
installer which will generate a CSR. You pass this CSR to your external
CA and get back a cert. You then pass this cert and the CA cert and
re-run the installer. The CSR is always written to /root/ipa.csr.

A run would look like:

 # ipa-server-install --ca --external-ca -p password -a password -r EXAMPLE.COM -u dirsrv -n example.com --hostname=ipa.example.com -U
[ sign cert request ]
 # ipa-server-install --ca --external-ca -p password -a password --external_cert_file=/tmp/rob.crt --external_ca_file=/tmp/cacert.crt  -U -p password -a password -r EXAMPLE.COM -u dirsrv -n example.com --hostname=ipa.example.com

This also abstracts out the RA backend plugin so the self-signed CA we
create can be used in a running server. This means that the cert plugin
can request certs (and nothing else). This should let us do online replica
creation.

To handle the self-signed CA the simple ca_serialno file now contains
additional data so we don't have overlapping serial numbers in replicas.
This isn't used yet. Currently the cert plugin will not work on self-signed
replicas.

One very important change for self-signed CAs is that the CA is no longer
held in the DS database. It is now in the Apache database.

Lots of general fixes were also made in ipaserver.install.certs including:
 - better handling when multiple CA certificates are in a single file
 - A temporary directory for request certs is not always created when the
   class is instantiated (you have to call setup_cert_request())

This involves creating a new CA instance on the replica and using pkisilent
to create a clone of the master CA.

Also generally fixes IPA to work with the latest dogtag SVN tip. A lot of
changes to ports and configuration have been done recently.

We used to install it as ipa, now installing it as ipapython. The rpm
is still ipa-python.