Add Backend UI for Entry, Language Models

[bitboxer]

...and make sure the video is attached properly to the entry views.

[bitboxer]

This takes a bit longer because I am also adding some styles to the backend 😉 .

Preview here:

[bitboxer]

You can all now try the layout in the pr #54 . It uses BlazeCSS as css framework. With BlazeCSS we get:

• Flow-Based-Layout
• uses BEM and ITCSS
• Lots of components that are easily configurable
• Does not touch any elements, we can separate everything because of that.

[bitboxer]

Closed with #54