Faster stdlib logging

I keep reiterating that it would be nice if a couple of Python stdlib modules got compiled by Cython during Python's installation, simply because it makes them faster right away, without sacrificing compatibility. Besides the difflib module, another nice example I found is the logging module. The logging benchmarks in Python's benchmark suite run between 20% and 50% faster when the module is compiled. Especially the silent logging case is interesting with its ~50%, because a lot of log messages really never end up in a log somewhere, so you can leave more log statements in your code to activate them at need. And I'm sure there's still a bit more to gain here by adding a couple of static type declarations in the right spots of that module. Feel free to give it a try.