Fix failing interpolation tests on newer sympy versions

See merge request pycodegen/pystencils!126

SerialDataHandling: synchronization_function for tensor fields

See merge request pycodegen/pystencils!122

Fix {PyCuda,PyOpenCl}ArrayHandler.{zeros,ones,randn}

See merge request pycodegen/pystencils!125

Add dtype to DataHandling.add_arrays

See merge request pycodegen/pystencils!124

Make create_staggered_kernel work with OpenMP

See merge request pycodegen/pystencils!123

Add DataHandling.add_arrays

See merge request pycodegen/pystencils!120

Automatic Finite Volume and Volume-of-Fluid discretization

See merge request pycodegen/pystencils!121

This adds a function for lazy people who want to write

```python
dh = create_data_handling((20, 30))
dh.add_arrays('x, y(9), z')
```

instead of

```python
dh = create_data_handling((20, 30))
dh.add_array('x')
dh.add_array('y', values_per_cell=9)
dh.add_array('z')
```

because in most cases you want to use more than one array.

Opencl datahandling

See merge request pycodegen/pystencils!119

this to your children or students)

PointerType should be rendered differently in OpenCL backend

Allow functions for Field.coordinate_transform

See merge request pycodegen/pystencils!118