Sphinx gallery

• Rename solver.solver to solver.solve; load solve also into the main namespace as emg3d.solve.
• Adjustment to termination criterion for STAGNATION: The current error is now compared to the last error of the same cycle type. Together with this the workaround for sslsolver when called with an initial efield introduced in v0.8.0 was removed.
• Adjustment to utils.get_hx_h0 (this might change your boundaries): The calculation domain is now calculated so that the distance for the signal travelling from the source to the boundary and back to the most remote receiver is at least two wavelengths away. If this is within the provided domain, then now extra buffer is added around the domain. Additionally, the function has a new parameter max_domain, which is the maximum distance from the center to the boundary; defaults to 100 km.
• New parameter log for utils.grid2grid; if True, then the interpolation is carried out on a log10-scale.
• Change from the notebook-based emg3d-examples-repo to the sphinx-based emg3d-gallery-repo.