This change will make modem channels not be capped to 65536 channels.

For legacy compatibility, any numbers passed into modem.open() would be converted into a string (example: 64 -> "64")

This would prevent modem sniffers and also be fairly useful to prevent interference, especially when using wireless and ender modems.

I'm happy with the current system. It relatively simple, and provides a good base on which more powerful or secure primitives can be built (rednet protocols for arbitrary channels, the various modem encryption libraries, etc...)