Add bonds_color/bonds_width settings to GeometryPlot

[pfebrer]

Just as there are atoms_color and atoms_size, it would be great to have these settings for bonds so that users could quickly set them using whatever property they have.

[pfebrer]

There is no atoms_color and atoms_width settings anymore. They both have been merged in a more generic atoms_style setting. Accordingly, there should also be a bonds_style setting.