Try to make random_char_replacement clearer

(Not sure I was successful)
Make sure the dictionary is copied
fix bugs in new randomise layout
fix tests for new randomise layout
Add in .testr.conf for tox
Fix package imports
Fix tox configuration
fix pep8 issues
Merge pull request #10 from jhesketh/refactor

Try to make random_char_replacement clearer
Add support for fkeys to cascade
compact cascade fkeys into one method
make restore onupdate values a static method variable rather than global
fix pep8 issue
Remove unnecessary list casting and overhead
Move to new style attributes

Russell Bryant didn't love doc comments (they clutter up sphinx
output), so we're going to use a variable instead.
Merge pull request #12 from mikalstill/attributes-v2

Move to new style attributes
New name for anonymization variable.

Based on feedback from the code review for nova.
Return table name not model object name.
Merge pull request #11 from jhesketh/refactor

Add support for cascading foreign keys
Merge pull request #13 from mikalstill/attributes-v3

New name for anonymization variable.