PR#501 - FIX: Possibility of desync due to a defect in the signal connector

[RESTRICTED ACCOUNT]

Hello travelers gathered in the simtrans world tavern.
In the process of fixing the depot upgrade bug I seem to have gained a small amount of experience and leveled up from level 1 to level 2 (because I heard the fanfare sound telling me that I had leveled up) and noticed the incompleteness of my previous patch. My apologies for this.
I don't have any charged boosts, so my level increases are very slow. (´・ω・｀)

Anyway, let's move on to the main subject.
I thought it would be more convenient to connect signals from a GUI, so I created such a GUI, but the design was incomplete. This could have sometimes resulted in desync in the network. I think I have fixed it. Please check the pull request #501.

Also, some extended-specific tools that should have been replaced by merging from the standard may not have been correctly replaced with correct function names so far, which has also been fixed.

[jamespetts]

Thank you - now incorporated.