Template strings and other things

The PR allows the definitions of log templates using the `$template` parameter in `client.conf` as per http://www.rsyslog.com/doc/rsyslog_conf_templates.html

There are some other changes in `client.conf.erb` these:
* clarifty 'managed by puppet' comment and remove duplication
* move some configuration statements for SSL connection and PreserveFQDN so they're outside the local logging block and expose them for remote logging,  which should resolve #58