config: Add method to deep-copy a config and validate its contents. Deep-copying will be problematic if non-basic types are in there, so there's a new method to check that this is OK.

cov-core==1.15.0
coverage==3.7.1
mock==1.0.1
pytest==2.7.0
pytest-cov==1.8.1
pytest-mock==0.4.3