Don't die if we haven't defined PIWIK_{URL,SITE_ID} or can't contact the
piwik server
Merge pull request #1 from creffett/piwik

Don't die if we haven't defined PIWIK_{URL,SITE_ID} or can't contact the piwik server
Merge pull request #2 from creffett/registration-refactor

Registration refactor
Add administration tab for staff users