Profiling - 'all' option does not produce complete profiles for all topics

Summary

According to our documentation, we should be able to profile 'all' of the profiling topics by executing a command like:

BST_PROFILE=all bst build foo.bst

Which produces .logs and .cprofiles (binaries) for all of the topics. However, upon inspection, all topics do not appear to be correctly profiled. It seems that cProfile doesn't appear to nest properly.

Perhaps for now, we should just not recommend using 'all' in our documentation?