First commit to new extrusion branch. Previous functionality ported.
Fixed global attribute error when backend changes.
Extra flags added to OpenMP.

Conflicts:

	pyop2/openmp.py
OpenMP caching error and OpenMP args fixed.
IterationSpace gets a cache_key property using only extents and layers
Partition size fixed for general case.
Fixed unit test errors for sequential and OpenMP backends.
Fixed the OpenMP globals. OpenMP and sequential are compatible with trunk.
Extrusion test added.
Comments added for the new ExtrudedSet and ExtrudedMap classes.
Deleted debug comments in computeind.pyx.
Self-Review corrections. +8 instead of *8 when eliminating false sharing.
Computeind moved to pyop2 folder and added to ext.
Fixes to Map.
Fixing caching in CUDA.
Fix test_extrusion to be skipped in cases other than openmp and seq.
Fix opencl backend to use the new caching technique.
Code refactoring.
Fixed errors in extruded examples.
Removed one of the examples in extrusion.