Polish ui

Fixes a config parameter name. Removes a console.log, which got there by mistake. Fixes some css properties of the chat unread messages.

Turning video thumbnails into squares. Changes the size of the dominant speaker avatar and fixes some minor thing around those two.

Shared video, synchronized play/pause/seek/muting/volume, initial commit.

Fixes setting local video, default videoType. Fixes showing local video when there is no video device shown.

Creates first the container before setting avatar, cause the avatar set will check the large video container type and type may be missing. Fixes error 'container of type undefined doesn't exist':
>    at LargeVideoManager.getContainer
>    at LargeVideoManager.get
>    at Object.isCurrentlyOnLarge
>    at Object.changeUserAvatar
>    at Object.UI.setUserAvatar
>    at Object.UI.addUser

Add unsupported_browser.css to source-package

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>

Fix etherpad

Implements dialog for max users error

Ui container management and fixes

Fixes avatar that is shown, when we switch from container with muted video to container from other type, like etherpad.

Resizes large video on filmstrip toggle.

Always uses current video type to search for container that will handle it. Renames video container type to camera, to match the type ot the tracks. Add the same container to be used and for tracks with type of desktop.

Adds optional parameter to addParticipantContainer, make possible to create the SmallVideo outside VideoLayout and pass it to be displayed.

Merges damencho's PR for removing prezi. We still need to remove all prezi related strings from translations through translate.jitsi.org.

Example NW.js app.