v5.10: release MagIC 5.10
- Reduce the number of alltoall calls when finite differences are used
- Now use (theta,phi) instead of (phi,theta) layout for faster SHTs
- Make use of SHT_ALLOW_PADDING option of SHTns whenever this is available
- Make the native spherical harmonic transforms share the same API than the SHTns wrapper. This allows a significant reduction of the number of code lines at the price of slower native transforms.