Make intelligent patching mode 4 controllable with the ctrl modifier.

Intelligent patching mode 4 often just always prefers option A (outgoing connections). But if the user actually wants option B (incoming connections), he can't get it because option A was chosen. This is confusing, which is why mode 4, while very useful if it works as intended, can be rather difficult to use right now.

We therefore now take into account the status of the ctrl modifier, which simply reverses our choice of option A or B, so that the user now has a way of getting option B even if option A is preferred (and vice versa). If the ctrl modifier isn't pressed, mode 4 works exactly as before, so this change is fully backwards-compatible.

See also the discussion in #262.