Allow for better $logroot management

This commit now allows you to set the directory permissions on the default
$logroot directory by exposing $logroot_mode in init.pp. It also adds a
$logroot_ensure parameter to apache::vhost that can toggle the creation of a
vhost's logroot resource.
Added missing syntax highlight to 1st apache::mod::php example
Merge pull request #807 from Ginja/expose_logroot_mode

Exposed $logroot_mode in init.pp
Merge pull request #832 from thatgraemeguy/master

Added missing syntax highlight to 1st apache::mod::php example