adding counter column
adding counter support to update statement generator
adding support for using set statements for counter columns if there is no previous value, reformatting
updating the model and query classes to handle models with counter columns correctly
adding tests around counter columns
setting counter column default instantiation value to 0 (not None)
adding tests and checks to model definition constraints
Merge branch 'master' into counter-column
Merge pull request #97 from cqlengine/counter-column

Counter column