First stab at Cython extension module for Plan construction
Access thrcol through c array
Access nelems through c array
Use cstruct instead of dict
Fix unit test to explicitly pass partition size
Add plan selection logic
Skip matrix coloring test when using legacy plan objects
Add python/c bitwise plans comparison support code
Refactor plan unit tests
The OpenMP backend requires matrix coloring
For Mat par_loops without indirect Dat arguments, ind_map and loc_map may be empty
add extra type information
Conditionally compute staging and thread coloring
Rename some variables and add comments for clarity
Add parser option --legacy-plan to select legacy C plan

The default is using the Python plan. This requires changing the
configuration parameter to python_plan to make it compatible to
argparse.
Merge pull request #149 from OP2/plan-ng

Cython implementation of the plan function

Supports matrix coloring and selective computation of staging and thread
coloring only as needed.