Fix Bug 903089 - robots.txt changes

In production, add the following line to robots.txt:

disallow: /*/newsletter/existing/*

In dev, staging, etc:

user-agent: *
disallow: *

settings.SITE_URL is used to determine if we are in production.

In etc/httpd/global.conf, add a RewriteRule to serve robots.txt from
Django.

Add robots.txt to settings.SUPPORTED_NONLOCALES to eliminate redirect.
Bug 904237  Update persona.html and persona.less
Copy changes to focus on sign-in-with-email behavior of Persona
Made relying party example block generic, named it rp-example (from previous RP used trovebox)
Merge pull request #1156 from jgmize/bug-903089-newsletter-robots

Fix Bug 903089 - robots.txt changes
/robots.txt Content-Type: text/plain
Merge pull request #1161 from jgmize/robots-content-type

/robots.txt Content-Type: text/plain
Bug 905086: enclose all strings in l10n calls
Merge pull request #1162 from pascalchevrel/Bug-905086_make_about_page_localizable

Bug 905086: enclose all strings in l10n calls
Fix clipped video-js skin image sprite
Bug 905144
Merge pull request #1163 from sgarrity/bug-905144-video-js-sprite

Bug 905144 Fix clipped video-js skin image sprite
[bug 899978] Update social share widget for Firefox OS page
Merge pull request #1120 from alexgibson/update-social-share-widget-bug-887147

[bug 899978] Update socialshare widget for Firefox OS page and add Facebook l10n helper
Fix bug 905222: Redirect Privacy Policy PDF.

This version of the Privacy Policy is obsolete. We no longer link to it,
but users could still be accessing it directly.
Add poster frame attribute to video() helper
Bug 905347
Use video() helper for videos across bedrock
Bug 905348
Bug 904765 - update Flicks promo on home page
[bug 905144] cache bust updated video-js image sprite
Merge pull request #1168 from alexgibson/bug-905144-fix-clipped-video-js-skin-image-sprite

[bug 905144] cache bust updated video-js image sprite
Fix Bug 887245, point plugins with no update URL to google not to plugincheck itself
Merge pull request #1151 from ossreleasefeed/bug887245-plugincheck-should-not-link-to-self-on-update-button

Fix Bug 887245, point plugins with no update URL to google not to plugincheck itself
change the second parameter of platform_img() to be a simple dictionary instead of **kwargs. This allows naming the keys however we want instead of having to name them as valid python vars. Useful when the attribute has a dash in it. Update all current uses of platform_img to work with the new attribute type.

remove whitespace