Fork languages edited in the new editor (#463)

I used Janet's suggestion of simply forking everything edited in the
new editor.
Fixed UniSubURLValidator to load the Site object lazily

This is needed to make the unittests work
Added model class that tracks videos moving from team to team
Fixed attribute error in the billing test
BillingReport refactoring

Added a new billing report types for approval/delivery teams.  It
still needs to be implemented.  Refactored the process() method and
split it up into row generation and CSV file formatting.  Refactored
the tests a bit as well.
Couple of speedups for the unittests

Better mocking for celery tasks.  For example sometimes we call
update_one_team_video and sometimes we call
update_one_team_video.delay.  For both of those we want to mock out
the call.

Mock out resetting the widget video cache.

These two changes speed up creating team videos and moving them to a new
team by over 10x.
Implemented billing report for approval-type teams

Fixed BillingReport.__unicode__ when the primary key is not set.
Made approval billing reports not select rejected approval tasks

Added tasks.complete_approved/complete_rejected.  I keep writing these
methods in the unittests, so we might as well add them to the Task
class.  Made Task.complete() return the review task for rejected
approval tasks.
Remove subtitler/reviewer replace with approver for billing reports

Janet points out that we'll have the subtitler/reviewer in the report
to pay people, so we don't need it here.

Fixed code that calculates names to use unicode() instead of
full_name.  This should result in "<first_name> <last_name>".
Added Translation? column to the approval billing reports.

Changed row data so we use booleans for boolean columns.  The CSV
writer can handle those fine.
Renamed billing record types and removed the old type

In the UI we now call them "Crowd sourced" and "Professional
services".  In the backend we call them TYPE_BILLING_RECORD and
TYPE_APPROVAL.

Fixed a bug with the TYPE_BILLING_RECORD reports, were we weren't
generating minutes correctly.
Added billing type to pay users who perform subtitling/review work
Fixed attribute error with the billing form
Fork dependant languages as well when edited in the new editor
Added hint abut forking to the new subtitle editor template
there was an extra trailing " at the end of the sentence
checkpoint
Reworked the docker dev environment stuff

Moved code to a python package.

Consolidated the build-images.py and services.py script.  Now there's
one command to start everything.

Improved the readme.
Bunch of fixes to the docker-dev stuff

Went away from trying to store imageids for all the images.  I realize
that those will change and there's not an easy way to implement what I
wanted.  Replaced it with a flag you can pall to startup.py

Detect when images are removed, but the cidfile still exists.  If that
happens we remove the cidfile and restart the image.

Made the amara-dev Dockerfile not depend on the main one.  I think
this is better since the main one installs a bunch of stuff that we
just replace when we mount the git repo in /opt/apps/unisubs.

Various fixes to the scripts/modules.
Added code to initialize the mysql database