Remove the "Change MAC Address" screen, and simply generate a new (random) one upon pressing the button.
Merge pull request #6518 from thedax/ui-rand-mac

Remove the "Change MAC Address" screen, and generate a random one instead.
Fix Win32 builds and remove the new MAC address editing prompt.
Merge pull request #6577 from thedax/win32-buildfix

Win32 buildfix. Remove the new MAC address editing prompt, too.
Update native with a required new Choice subclass.
Change the MAC address randomiser, proAdhoc server editor, and post processing shader choices to ChoiceWithValueDisplay, so we can see their values.
Merge pull request #6579 from thedax/ui-minor

Tweak the UI a bit.