When updating from the IEBC API, also use its pictures
Update the cache directory for today's data
Ignoer downloaded candidate images
Another API update on March 1st
Add some more "same person" matches to compensate for a bug

Unfortunately, the external_id field wasn't being set for
candidates that had to be newly created, so these false
uncertainties arose.  This adds entries for all of those in
names-manually-checked.csv so that they will be associated
correctly.
Add a method to show current external IDs of positions for a person
Add "Contest Type" and "Mz Candidate Code" to names-manually-checked.csv
Remember to set the external_id on newly created Positions