a few copyedits on bulk user invites
didn't need to move gutter watermark up
BUGFIX: S3 backups failed when using a region

TRIVIAL: updated fog gem to latest version (1.22.1)
BUGFIX: fixed algorithm used to remove old backups
add glyph to sign in button on topic private page
minor copyedit on email-in
Merge pull request #2519 from techAPJ/fix_invite_search

FIX: don't hide invite search box while filtering
FIX: selectively disappear invite search box