Minor estethic changes
allow contracts to be disabled with ENV variable
Merge pull request #22 from adampalay/master

allow contracts to be disabled with ENV variable (by adampalay)
Added credits
Credits in docs
bumbed up version number
Update README.rst
Update CREDITS.rst
Updated credits
Update CREDITS.rst
Update CREDITS.rst
Update README.rst
Added more docs and link to presentation. Cosmetic enhancements
Scoped variable RValue
Python3 fixes
Use $ instead of ! for scoped variables
Merge pull request #27 from ChrisBeaumont/scoped

New "$var" syntax allows contracts to refer to Python variables in scope (Chris Beaumont)
Allow args/kwargs to be passed to Extension contracts
Merge pull request #28 from ChrisBeaumont/multiarg

Allow args/kwargs to be passed to Extension contracts (by @ChrisBeaumon)
Merge branch 'master' into env_fault