Update examples/blocks.py to use the modern API for generating the respective blocks with a checkered cubemap material and rounded edges.

Update examples/CollideBlocks.py to a modern API as well, along with other examples which use blocks.py (some should just be deleted instead due to being redundant or obsolete).

These examples should use a white background for cleaner screenshots.

While working on this task you should join and remain in #PySoy on Freenode to get help, feedback, and guidance from mentors and other developers.

When you've done, commit your work and post the resulting changeset url to this task.