Make dogtag an optional (and default un-) installed component in a replica.

A dogtag replica file is created as usual. When the replica is installed
dogtag is optional and not installed by default. Adding the --setup-ca
option will configure it when the replica is installed.

A new tool ipa-ca-install will configure dogtag if it wasn't configured
when the replica was initially installed.

This moves a fair bit of code out of ipa-replica-install into
installutils and cainstance to avoid duplication.

https://fedorahosted.org/freeipa/ticket/1251

install/po/Makefile.in

@@ -53,6 +53,8 @@ PY_EXPLICIT_FILES = \
      install/tools/ipa-host-net-manage \
      install/tools/ipa-server-install \
      install/tools/ipa-ldap-updater \
+     install/tools/ipa-dns-install \
+     install/tools/ipa-ca-install \
      ipa-client/ipa-install/ipa-client-install
 
 PYTHON_POTFILES = $(PY_FILES) $(PY_EXPLICIT_FILES)