Allow to add annotations on video

• if no Openseadragon instance, use a VideoViewerReference (based on OSDReferences) to get canvas size & DOM element
• add 2 number fields to specify annotation start/end
• speed up build by removing umd (not used in our dev setup) and demo build
• remove conflicting dependencies Both removed dependencies are installed at a lower version by another dependence (immutable is installed by draft-js-*)