The power monitor can now be queried for information about the network. They
are retrieved from the associated switching station.
Also export information about the attached batteries.
Add the EU_string helper function
In comparison to pretty_num it uses SI prefixes, adds "EU" (e.g. kEU) and rounds the number for readability
Add a constant_digit_count boolean setting
delete back/bottom texture for power monitor
use "machine bottom" for bottom of force field generator
add cable connection overlay, use it on various machines' bottoms/sides, as appropriate
This fixes several issues:
* More than one switching station could become active on large networks
- Switching stations now semi-permanently become disabled if another is present
- Power monitors have been added to replace the function of "slave" switching stations, to discourage overuse of switching stations
* Networks did not reliably "split" when cutting a cable
- I "may" have caused this issue, but I believe it is solved by this
* Machines did not run without a player near the switching station
- Active switching stations now forceload themselves, and free the forceloaded block if disabled, dug, or disconnected
- Machines are only loaded to run them (as before), so only one mapblock (or two if the bottom edge of the switching station is a mapblock boundary) is loaded
- Cables are still only loaded during a full network recalculation
