Remove duplicate mixing in of Discourse.Presence

AdminEmailIndexController and AdminEmailPreviewDigestController explicitely mix in Discourse.Presence, but they extend base classes Discourse.Controller and Discourse.ObjectController that already mix in Discourse.Presence, so this explicit inclusion is redundant.
Added screencast.com to whitelist.rb

Adding onebox support to screencast.com could be useful.
update mini profiler
flamegraph update to support embedded graphs
Use two lines per topic list item on mobile
Remove posts icon and make post count bold in mobile topic lists
Add email icon to password reset email button
Add wrench icon to Edit Category button
Remove duplicate list.js.handlebars
Changes to support Spoiler Alert plugin
FIX: Broken spec
update mini profiler on rails 4
optimise regular job to avoid touching posts that have not changed
remove unnecessary (empty) view class

Discourse.ApplicationView does not provide any functionality above what
already automatically happens via Ember's "convention over
configuration" behavior and is therefore redundant.
Merge pull request #1448 from velesin/remove_redundant_presence

Remove duplicate mixing in of Discourse.Presence
mobile: fixed quote control jump
make category's RSS feed actually order by topic.created_at
if we have not automatic assets, don't try deleting them
Merge pull request #1454 from awesomerobot/master

mobile: fixed quote control jump
Merge pull request #1455 from alxndr/category-rss-ordered-by-created_at

make category's RSS feed actually order by topic.created_at