Summary
Add a way to use instantiated C++ template classes from Python that looks a bit more like the C++ syntax.
For example:
# This:
simulation = OffLatticeSimulation2_2(cell_population)
# would become:
simulation = OffLatticeSimulation[2][2](cell_population)
# and this:
cell_population = VertexBasedCellPopulation2(mesh, cells)
# would become:
cell_population = VertexBasedCellPopulation[2](mesh, cells)