Update dhcp module path for Ubuntu precise.
Update dhcp module path for Ubuntu precise.

In Ubuntu precise, the dhcp dir is /etc/dhcp for isc-dhcp-server.

The changes have been only tested on precise. and I'm uncertain how far
back this change was put in place since the filelist have not changed:
http://packages.ubuntu.com/natty/amd64/isc-dhcp-server/filelist
http://packages.ubuntu.com/oneiric/amd64/isc-dhcp-server/filelist
http://packages.ubuntu.com/precise/amd64/isc-dhcp-server/filelist

Conflicts:
	manifests/params.pp

varunarya10/puppetlabs-dhcp,bmjen/puppetlabs-dhcp,treydock/puppetlabs-dhcp,javierwilson/puppetlabs-dhcp,archii/puppetlabs-dhcp,ocadotechnology/puppetlabs-dhcp,trovitsys/puppetlabs-dhcp,ocadotechnology/puppetlabs-dhcp,treydock/puppetlabs-dhcp,jearls/puppetlabs-dhcp,simon3270/puppetlabs-dhcp,archii/puppetlabs-dhcp,bmjen/puppetlabs-dhcp,puppetlabs-incubator/puppet-dhcp,puppetlabs/puppetlabs-dhcp,jearls/puppetlabs-dhcp,michaelweiser/puppetlabs-dhcp,varunarya10/puppetlabs-dhcp,puppetlabs/puppetlabs-dhcp,michaelweiser/puppetlabs-dhcp,trovitsys/puppetlabs-dhcp,JioCloud/puppetlabs-dhcp,simon3270/puppetlabs-dhcp,javierwilson/puppetlabs-dhcp