Add Piwik as a submodule for stats tracking.

This stats implementation tracks a bunch of other sites as well, but needs to be deployed somewhere. Over time this may end up in some kind of master repo rather than as part of jeremyfelt.com
Copy over existing nginx config from server
Add method to push stats to deploy script
s/path_config/stats_config/
Copy stats nginx config on config deploy
Clean up the stats nginx config, something wasn't pretty
Remove the piwik submodule, apparently it's a PITA to install
Merge branch 'master' of github.com:jeremyfelt/jeremyfelt.com

Forgets to pull before committing....
Update WordPress tracking commit