Use 64-bit integers for signals

[coppercoil]

"A second tier of circuit items could be added to not break existing 32b hacks."
The problem is that signals are stored the same regardless of the entity type. This would only increase implementation complexity.

Complexity increate is the way how software introduces new things. Almost everything increase complexity, this is normal. There's another question: is it acceptable increase? To be more precise: how is made the decision about complexity acceptance if it would be released in Y days, and Z implementation will be used. There are at least three unknown members in this question. Let developers decide.