Create ctypes structs and wrapper classes for the various ckernel interfaces
Fix flags tests in the PEP 3118. Fixes gh-10
Add error checking when constructing a null nd.array. Fixes gh-4
Add intptr and uintptr to datashape and the ndt namespace
Move ctypes definitions from ckernel.py to ctypes_types.py, other tweaks
Starting tests for the ckernel builder
Add tests of getting assignment kernels from python
Tweak _lowlevel assignment ckernel creation to include metadata
Add tests for the ckernel_deferred exposure to python
Got scalar numpy ufunc -> ckernel_deferred adaptation working