Use omega instead of dividing by tau0 in the relaxation code.
Move some functionality into the sym_codegen module.

Change KernelCodePrinter to minimize the number of division operations.
Add an explanation for why we modify _print_Mul.
Use larger L1 cache and PTX annotations by default in CUDA code.
Add an option to disable the L1 cache.
Add support for the propagate on-read scheme.
Add code to collect goldens.
Add targets to make and test goldens.
Save the git revision when making goldens.
Remove dist dumps from scope as soon as they are saved to disk.
Only include src lines in the PTX code if using CUDA 5.0+.
Add info about drawing walls in the pygame visuslization interface.
Move the example code from the main page to the "Running simulations" chapter.