Advice on logging in IO classes
Merge pull request #142 from rproepp/master

Docs on logging in IO classes
move neo.core test files into own directory
move generate_datasets to neo/test directory
make generate_datasets annotations consistent
refactor fake_neo to be more complete and predictable
refactor test_generate_datasets
improve merge functionality and documentation
refactor assert_neo_object_is_compliant
refactor container core tests
create common container base class and refactor container classes to use it