Add param for default log format, for vhost templates
Sort params
Use title to name logfile rather than servername

This allows us to specify more than one servername in hiera when defining a
vhost.
Use vhost name rather than servername for logfile

This allows us to specify more than one servername in hiera when creating
a vhost, proxy, etc.
Merge pull request #31 from hmrc/vhost-logging

Prefer the vhost title to the servername to name logfile