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.  This patch resolves all outstanding puppet-lint violations.