The previous name for this was rather misleading. It isn't an actual
jump like you'd expect the `jp` instruction to behave as. Instead, it
behaves more like a `farcall`.
This also makes it consistent with its current command ID name of
`TX_FAR`.
Renamed a bunch of files, most of them one-off functions, to better fit
the general snake_case naming scheme. Also renamed some awfully long filenames.
