fix preprocessor macro usage in generator code
add tutorial section on naming C function parameters
refactor test
support tuples as compile time constants
add test case for more complex compile time expression and add tree assertions to others
extend list of builtins usable in compile time expressions
extend switch statement test to include compile time tuple
fix Py3 test issue
extend compile time constants error test case
support None as compile time constant expression
Fix buffer pure mode regression.
Speccial case the unused '_' in warnings.
Remove archaic disable_function_redefinition option.
Use wraparound and boundscheck directives for memory view slices.