Fix check_nrpe_ng for Python 3
Require Python 3.4+

Forget about trying to support 3.2 or even 3.3. The SSL API functions
just aren't there, and copying in chunks of Python 3.4 into nrpe_ng is
stupid.
Remove SSL compat code.
Exterminate 'import nrpe_ng' and friends
Only grab __version__ from version.py
Use hierarchical loggers, remove PROG

This effectively guts __init__.py completely.
Decompose http.py into a small package