Add path_prefix & path_suffix parameters

Expose path_prefix & path_suffix config options
Add spec test cases for path_prefix & path_suffix
Rename diamond.conf template to have .erb suffix
Update diamond.conf template to use instance variables
Allow for custom Graphite handler and clean up template
Update to allow additional handlers and expose stats_d config

Add stats_host & stats_port to configure StatsdHandler
Allow extra_handlers to be passed along with additional handlers
to be configured
Merge pull request #3 from jbouse/master

Add additional parameters and cleanup template