Remove extruded bcs code

The bcs should be applied to a Map, rather than the iteration space.
Sketch implementation of "python" par_loops

This allows (for Dats and Globals) par_loops to take a python function
as a kernel argument.  Only very lightly tested.
Copy data back out in python par_loop

When we pass a view into the kernel function, the internal indexed
assignment will create a copy which we then need to splat out to the
actual data.
Raise error for further unimplemented case
Remove overcautious exception
Add tests of python par_loop
Fix python par_loops in conjunction with device backends

We need to explicitly manage moving data from the device and updating
its state.
Merge pull request #392 from OP2/py_parloop

* py_parloop:
  Fix python par_loops in conjunction with device backends
  Add tests of python par_loop
  Remove overcautious exception
  Raise error for further unimplemented case
  Copy data back out in python par_loop
  Sketch implementation of "python" par_loops
Rework SparsityMap to DecoratedMap

To apply implicit (extruded top and bottom boundary conditions) to Maps,
we need to record whether such a bc should be applied to the current
Map.  We can't modify the Map itself, since it may need to be used in
unmodified form.  Instead, rework the SparsityMap object to a more
general DecoratedMap that allows us to attach arbitrary data to a Map,
and use it to store both the iteration_region of a Map (for building
sparsities) and any implicit boundary conditions that may need to be
applied.
Reimplement top and bottom bcs for Mat assembly in extruded

Now that the Maps themselves keep track of whether any implicit boundary
conditions are to be applied, we can add back the code generation that
places negative values in the maps and do so on a map-by-map basis.
This means that we only apply bcs to the relevant part of a MixedMap.
Merge pull request #386 from OP2/ext-mixed-bcs

* ext-mixed-bcs:
  Reimplement top and bottom bcs for Mat assembly in extruded
  Rework SparsityMap to DecoratedMap
  Remove extruded bcs code
Bump version to 0.11.0
turn off O3 compilation