Bug 976230 - 'make a banner' templates
Integrate embed templates into detail view.
Replace progress bar with macro throughout generator.
Hook up banner list in dashboard.
Bug 993237: Add aggregation command and overwrite old stats upon update.

- Adds a command for aggregating clicks and downloads that are older 
  than 90 days.
- Updates the collect_ga_data command to accept a date argument for
  easier testing, and to overwrite existing stats instead of raising
  an error due to unique constraints.
Move make-banner.styl into base project

And update the @import path
Fix tests broken by integration commits.
Add product details and media_htaccess to nightly_update.sh.
Fix bug 1000357: Add pontoon.js when DEV = True.
Add path for server's special version of PyOpenSSL to PYTHONPATH.
Fix link details URL to have a locale.
Disable submit button on customize screens until option chosen.
Show native language names in generator and sort alphabetically.
Add old datapoint aggregation to nightly update.
Show 100 entries on leaderboard and lazy-load avatars.
Hide banners that are not visible from the banner list and customize.
Only display categories that have visible banners.
Do not disable default options in image generator.

Otherwise, you get a weird bug where hovering over an enabled option and
clicking twice outside the select selects the option you hovered over
but doesn't change the displayed option.
Remove duplicate categories from category display.
Add newsletter form plus a few other tweaks

* Updated milestone style
* Added news sidebar copy
* Added blank avatar
* Optimized images
* Added noscript notice