Update metric URL basepoint

Change in routes and cubism metric context
Bring graphite backend inline with new functionality

Graphite does support epoch in the from (start) and until(stop) fields, so
that's nice. Also change to use old Net::HTTP retrieval. Using open-uri errors
on graphite error without passing back the odd error message for parsing. Will
cause issues when graphite is on a HTTPS url.
Update generic backend proforma to match new 3st format
Remove old flatfiles, add new Geneator

Per README file, use generator for creating and testing new flatfiles
Remove unrequired `get_metrics` function
remove unrequired to_seconds function from application helper
bring flatfile backend type inline with new 3st format