VTK test

Tried to make the code from last time a bit clearer by splitting it into two files:

vtkscreen.py and test2.py

conversion to video again by first converting PNG to JPEG:

mogrify -format jpg -quality 97 *.png

And then encoding JPEGs into a movie:

mencoder mf://*.jpg -mf fps=25:type=jpg -ovc lavc -lavcopts vcodec=mpeg4 -ac copy -o output.avi -ffourcc DX50