Drop usage of six

Stop using pytools.{any,all}

See merge request !132

Furo doc theme

See merge request !131

Fix a build failure (kernel cloning introduced in 2.1, not 2.0)

Add arm64 support for Apple Silicon

Add arm64 support for Apple Silicon

See merge request !130

Skip rectangular copy tests on Apple

https://github.com/conda-forge/pyopencl-feedstock/runs/1422085871

Handle contiguity and reshape for empty arrays like numpy

Array: Handle no-queue in __str__, __repr__ more gracefully

Add note to install docs about mixing conda forge and pypi installations

Array.__repr__: Make CL arrays visually distinguishable from numpy arrays

Fix doc reference to enqueue_copy in subst.rst

Don't use enqueue_fill_buffer for large arrays on NVIDIA

Co-authored-by: Andreas Klöckner <inform@tiker.net>