tests: add test for empty CA certs file smf reported that an environment with no loaded CA certs resulted in a weird error. I'd like to detect this a bit better so we can display an actionable error message. The actual error being globbed over in this patch is "unknown error" with a ssl.c line number. That isn't useful at all.

internals: move the bitmanipulation routines into its own file This is to allow more flexibility with the C sources -- now the bitmanipulation routines can be safely imported without importing Python.h