WIP: Fix Style Violations

The graphite module has numerous style guide violations.  While
harmless to the end user, they make this module more of a headache
to work with.  This patch fixes a number of style guide violations
and results in a clean puppet-lint check.

Closes-Bug: #1273400

Note: this patchset is based on the assumption that https://github.com/CiscoSystems/puppet-graphite/pull/18 merges first, so it will need rebasing/squashing before it can be merged.  I'll take care of that once the other pull goes in, but wanted to post this up sooner rather than later for eyeballing.