Resolve "MPI safe termination if greens function is unstable"

Closes #186

See merge request !109

Resolve "All hamiltonians in one binary"

Closes #166

See merge request !107

Merge branch '166-all-hamiltonians-in-one-binary' of git.physik.uni-wuerzburg.de:ALF/ALF into remotes/origin/166-all-hamiltonians-in-one-binary

Resolve "Do all plain text writeouts of floats in scientific format"

Closes #164

See merge request !105

Corrected bug in Hubbard Hamiltonian (Ham_V routine) that arises for the bilayer  honeycomb lattice.

Revert commit intended to the branch ALF-2.0: 'Change links to ALF-2.0 branches of ALF and pyALF; include script and folder for arxiv submission.'

This reverts commit db0cf476.