RTL support is broken for chooser

[ayamws]

Hey.

the Arabic URL is not working at all: https://creativecommons.org/choose/?lang=ar

Thanks

[TimidRobot]

@ayamws thank you for reporting this bug!

This appears to impact all RTL languages (ex. ar, he, fa)--GitHub issue title updated.

traceback from staging environment:

URL: http://stage.creativecommons.org/ccEngine/choose/?lang=ar
Module paste.exceptions.errormiddleware:142 in __call__
>>  app_iter = self.application(environ, sr_checker)
Module cc.engine.app:113 in __call__
>>  return controller(request)(environ, start_response)
Module cc.engine.chooser.views:534 in chooser_view
>>  'chooser_pages/interactive_chooser.html', context))
Module cc.engine.util:125 in render_template
>>  rendered = template.render(context)
Module jinja2.environment:1008 in render
>>  return self.environment.handle_exception(exc_info, True)
Module jinja2.environment:780 in handle_exception
>>  reraise(exc_type, exc_value, tb)
Module /srv/ccengine/src/cc.engine/cc/engine/templates/chooser_pages/interactive_chooser.html:1 in top-level template code
>>  {% extends "macros_templates/engine.html" %}
Module /srv/ccengine/src/cc.engine/cc/engine/templates/macros_templates/engine.html:62 in top-level template code
>>  href="{{ request.staticdirect('cc6/engine-rtl.css') }}" />
Module cc.engine.staticdirect:13 in __call__
>>  static_direction = self.cache[filepath] = self.get(filepath)
Module cc.engine.staticdirect:45 in get
>>  self.remotepaths[section].rstrip('/'),
KeyError: 'cc6'

[TimidRobot]

This issue broke the chooser for approximately 490 million people