Merge pull request #16 from martabel/theodul-pass-player

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Removed unnecessary things from the UI; greyed out segment forward and backward buttons; implemented time updates and manuel time updates in the UI
made sync more stable
Seek-bug in video.js-sync
Added theodul player to role anonymous in security xml
adapt description tap plugin to new code style and insert the description of the mediapackage if available
add dummy text to slide tab plugin
style videodisplays