Have multiple "preinstalled" programs

[certik]

I think there should be some good example as the default, probably the Mandelbrot (#5).

Then there should be a menu:

• Add menu to select examples to run #59

which if you click you can select another example, and we populate it over time with some very good demos. Some ideas:

• Mandelbrot (grayscale): Mandelbrot demo: show the image #11
• Mandelbrot (color): Add Mandelbrot in color #13
• Plotting (we'll expose a function plot(x, y, label) which will take two arrays x and y and add it to a plot, with a label)
• Some numerical solver, say for Schroedinger equation, and plot the results
• Interactive widgets --- the compiled function can accept an integer parameter as an argument, and one can then hook it up with a slider, when the slider is moved, it would call the function again with a new value. The result would be immediately shown.
• Image manipulation, such as Gaussian blur, etc.
• Experimental features: template (generics) examples