Improvements for video presentation

[fedefalag]

Potentially interesting features when presenting videos:

• presenting at different positions on the screen
• presenting the same video a certain number of times
• possibility to skip certain frames (?)
• video file as input, extract the frames and present those to render the video

[Remi-Gau]

• Make the function general enough so that it can handle movies and series of images.
• create high level "abstract" functions loadMovie and playMovie