Major update with many new features:
- Elastic, dielectric, and piezoelectric tensors are now supported.
- Wave function coefficients are now desymmetrised on the fly, meaning `wavefunction.h5` files are much smaller.
- New tool to extract wave function coefficients that removes the `pawpyseed` and is much faster. This is a python only implementation and doesn't require compiling any additional codes.
- Mesh properties (scattering rates etc, energies, velocities) stored in a separate mesh.h5 file which is much smaller and faster to read.
- Revamped unit tests.
Lots of bug fixes, including fixing compatibility with quadpy.