Bump __version__ to 0.10.4, update CHANGELOG w missing releases

Prepare CHANGELOG.md for a new (major) release

Bump version to 1.0.0-community-alpha as HEAD is no longer Py2-compat

unit tests fail in Py2 w syntax errors
unit tests still fail in Py3 w import errors

Bump __version__ to 0.10.7

Bump __version__ to 0.10.6

Bump __version__ to 0.10.5

Merge pull request #392 from raccoongang/GREENHOST-252-remove-play-in…

…-the-loop

[GREENHOST-252] remove play in the loop

Merge pull request #387 from raccoongang/arsentur/feature/hide-xblock…

…-controls-for-vimeo

[LETSTUDY] Remove xblock controls for Vimeo backend

Merge pull request #383 from raccoongang/GREENHOST-198-fix-bug-with-p…

…lay-video-on-chrome

[GREENHOST-198] fix bug with play video in chrome

Merge pull request #380 from raccoongang/GREENHOST-198-fix-broken-mar…

…kup-and-progress-bar

[GREENHOST-198] fix broken markup and progress bar