plasma in python - 1.3

A demo effect using a palette in 8-bit mode to create a visually appealing experience. This program is based on C++ code written by Alex Champandard, from an article on demomaking (url: http://www.flipcode.com/archives/The_Art_of_Demomaking-Issue_04_Per_Pixel_Control.shtml).

Changes in v1.3: Various tweaks. Got rid of the create_plasmas.py file; I decided to include its functionality into the main plasma.py file. Now when it is run, it'll detect the presence of the raw files, or create them if necessary.