Fix a silly mistake: the point was to only dump JSON at the end
Explcitly sort the parties before dumping to JSON
Don't include the random ID of each identifier

This isn't useful on other systems and makes the diffs noisier when this
file is updated.
Don't include instance-specific URLs when dumping party JSON
Add a comment about why we remove images from the JSON dump
Fix: use the original EC ID in the electoral-commission identifier
No longer hardcode the PopIt DB name in reset-mongo.js

To remove all the persons, organizations, memberships and posts from
your PopIt instance you should now do:

  bin/reset-mongo.sh popitdev_candidates-posts

(... instead of previously where you'd have to edit reset-mongo.js and
run "mongo < reset-mongo.js")
Update dumped JSON after updates to its generating command