Default Timeline module

[voylin]

Should interact well with #102 and be an example for people to easily figure out how they can make their own Timeline Module. It will have all the basic necessary features, with not too many extra bells and whistles. There may come a more fully features Timeline module which people can switch to later on, but for the beta and first release, this basic timeline with all needed functionality to edit video's should be more then enough for 99% of the people using GoZen.