escape gravatar URLs to comply with W3C standards

This fixes an HTML validation error due to & not being properly escaped on the gravatar URLs.
fixes user specs about ampersands in gravatar URLs
Merge pull request #2287 from vikhyat/badge-system

Display username and granted_at on badge page
BUGFIX: pull hotlinked images job wasn't properly handling the InvalidParameters exception
BUGIFX: generate avatars when using S3 store
Don't show link counts in the body of posts for internal links. They are
already in the sidebar.
Allow admins to choose if groups are visible or not.
add pluralization rules in ember for Korean (ko)
remove unnecessary css witdh
SECURITY: self XSS by admin by editing badge name
UPGRADE: sidekiq to sidekiq 3.0
FEATURE: alllow unicorn master to fork sidekiqs, keep alive coming
FEATURE: unicorn sidekiq will restart sidekiq on complete failure.

(checks every 30 minutes for complete failure)
BUGFIX: caching sass is not valid due to "import" being used
BUGFIX: backups logs page was busted since last Ember update
Update README.md
Update README.md
FEATURE: warn the admin whenever we disable the download_remote_images_to_local site setting
display the copy & paste images hint to FF users too
Merge pull request #2288 from yomybaby/i18n_plural_ko

add pluralization rules in ember for Korean (ko)