Update message pinning to show up on the tab list with a few options to allow/disallow it and whether to allow anyone to pin messages

Currently only support soundcloud (futur providers will be add)

New version supports more representations of emojis containing an apostrophe and tooltips for emoji images using the title attribute which contains the text representation of the emoji (either shortcode or ASCII string).

Currently does not support *group* embed widget (like https://soundcloud.com/groups/made-with-ableton-live)

remove unnecessary line

Updating to support ServiceConfiguration.configurations stub method (meteor-velocity/meteor-stubs/#11)