Major refactor of the access module
The first step to sanity is a leap into the unknown? Create an object
to represent the access checks for each module instead of a bunch of
loose functions.
Converted all views and params.py to use the new access checker.
Main differences:
* arguments to a checker can be passed by using a tuple
* checkers are referenced by string, rather than directly
* the Checker constructor handles merging with child views
Patch by: Sverre Rabbelier
from query import *
from subqueries import *
from where import AND, OR
from datastructures import EmptyResultSet
__all__ = ['Query', 'AND', 'OR', 'EmptyResultSet']