Add newrelic browser-side monitoring.
Only mark manually added sources as manual
Add default affiliation to person
Use default affiliation in extractor, show on person page.
Include affiliation in /people api
Choose affiliation when selecting sources
Logic to relearn a source affiliation.

We use a decaying exponential average over a week's
worth of data to work out if a source should change.
Learn source affiliations after updating analysis.
Merge branch 'learn-affiliations'