Use Pythia8175GeneratorFilter and not the hack.
Revert "ptrig -> psel."

This reverts commit 1c39d19fd551de0340feacf47d78191ecd6193d9.
Revert "apply_vertex_selection default to None so empty string does nothing to reconfigure the cuts."

This reverts commit 7b0e62c9a4bf7e94085ff1dfc8b84d815f8bff1a.
Revert "apply_vertex_selection, which is exec'ed to configure the vertex/event selection and only write out passing events."

This reverts commit d13771d8cdf2086f3e804ff7fdb0e0f276370796.