Automatic Per-suite Layouts

This commit adds the ability to automatically detect per-suite Puppet
layouts. By using this, you don't have to manually specify the
location of the manifests, modules, etc for each suite.

This commit also adds the ability to specify the location of
the Puppetfile.

Documentation is also update.
Merge pull request #2 from jtopjian/jtopjian-per-suite

Automatic Per-suite Layouts