Remove dependency on S3

Now Graphiti only uses S3 if you tell it to do so. If not, it creates
png in public/images/snapshots.
Fix double escaping of graph render request parameters
Start documenting the JSON format
- refresh graphs every 60 seconds
Merge remote-tracking branch 'edmz/master' into auto_refresh
Should use strict comparison to check for optional function value.
Add UI control to auto-refresh graphs
Remove debugging
Add UI for controlling dashboard time frame

Fixes #35
Merge pull request #37 from kcrayon/patch-1

Should use strict comparison to check for optional function value.
Merge pull request #38 from ktheory/auto_refresh

UI for controlling auto-refresh
Adding logging so we can see when a refresh is happening
This is what is actually missing that causes our company dashboard to not refresh
Add drawNullAsZero graph option
Support always showing legend.

Support three states for the hideLegend graph option:
  * missing (default): show legend if fewer than 10 metrics
  * 'on': always hide the legend
  * false: always show the legend
ignore tmp
Replacing 'console.log's with 'Sammy.log'
Merge branch 'master' of github.com:paperlesspost/graphiti
Merge pull request #43 from kickstarter/more_graph_options

More graph options
Force snapshot graph urls to use the current Graphiti base url