on-demand tracing: Separate tracing functionality from main entrypoints
- Completed for wgl and cgl
- wgltrace.py and cgltrace.py were split into new *gltrace_tracefuncs.py script which generates _trace_* versions of each entrypoint and also take in an already known result (in case we want to force a particular result to be written) or can optionally make the actual API call to obtain the real result.
- Improved indentation in the generated files