Changes

* Landed infinite scrolling [https://github.com/mozilla/activity-stream/issues/417| #417]* In Review - In-line youtube/vimeo embedding[https://github.com/mozilla/activity-stream/pull/755| #755 ]

* Auto complete in search (regression from about:newtab)[https://github.com/mozilla/activity-stream/pull/765 | #765 ]* Delete/Hide/Block Improvement[https://github.com/mozilla/activity-stream/pull/778 | #778 ]* Improve first run experience[https://github.com/mozilla/activity-stream/pull/778 | #669 ]* replace about:home[https://github.com/mozilla/activity-stream/pull/778 | #724 ]* (stretch goal) Filtering in Timeline[https://github.com/mozilla/activity-stream/pull/416 | #416 ]