install: uid params, move oo-gear-firewall later

https://bugzilla.redhat.com/show_bug.cgi?id=1156291
Bug 1156291 - oo-gear-firewall fails during installation with mod_rewrite

oo-gear-firewall depends on node gem being loadable, which can depend on
correct configuration. In the case where mod_rewrite frontend is being
used, the node.conf needs to be updated from the default vhost before
the code will load properly. So oo-gear-firewall must be run only after
this has been done.

Additionally, the UID range used by oo-gear-firewall at install was
hardcoded in size; it now varies depending on PORTS_PER_USER as well as
the district first UID, if specified.