Adding more example-shaders

[azadad96]

This pull request adds some more shaders to the examples folder. One to blur the incoming video, three to do different kinds of edge detection and two to add some background effect.
Below you can find some screenshots of how these shaders look, note that both the background_* shaders are used together with the edge_detection one just because i think it looks cool, these two should also be changing over time, but don't, since these are only still images. Also the background_colors shader (second last) got a speed slider since taking these screenshots.