Bugfix: textures should be implemented as textures without changes

See merge request pycodegen/pystencils!73

Add __str__ representation for TextureDeclaration

See merge request pycodegen/pystencils!74

Add option to omit globals when printing C code

See merge request pycodegen/pystencils!75

Run opencl without pycuda

Closes #15

See merge request pycodegen/pystencils!77

correctly print RNG nodes

See merge request pycodegen/pystencils!78

- bugfix: loop counter of vectorized loop now correctly stored as SIMD vector with entries i, i+1, i+2, ...
- basis for in-kernel boundary handling

Fix printing of sp.Infinity/sp.NegativeInfinity

See merge request pycodegen/pystencils!71

For sympy, oo s a number. So pystencils prints a type infinity a double
INFINITY as INFINITY.0

Fix error in README.md: pystencils[pyopencl] -> pystencils[opencl]

See merge request pycodegen/pystencils!70

Small fixes

See merge request pycodegen/pystencils!69

Declare LoopCounterSymbols nonnegative

See merge request pycodegen/pystencils!68

This removed some checks like `ctr1 <= 0` from my kernels

Set assumptions for TypedSymbol/cast_func/IntegerFunctionTwoArgsMixIn the SymPy way

See merge request pycodegen/pystencils!66

Bugfix: this bracket should not be here (collate_types returns single type)

See merge request pycodegen/pystencils!63

Bugfix: Align calculation of number of ghost layers on GPU with CPU version

See merge request pycodegen/pystencils!65

Bugfix fields accessed for interpolator access

See merge request pycodegen/pystencils!62

Bugfix avoid east and west const

See merge request pycodegen/pystencils!64

For the calculation of the number of ghostlayers only relative accesses
should be considered like on the CPU version

Pystencils will print two const when printing an assignment to a const numpy.dtype.
With the new type interference, this case can now occur more often