Abstract platform-specific code

[branan]

This includes windows, GUIs, and input. Probably some other stuff too.

[dpogue]

The major issue at the moment for platform-specific code is the netcode. EAP seems to have a Windows NT version, a Windows 9x version (for the Mac Cider wrapper?), and an unimplemented Unix version. In some cases, he reimplemented existing working cross-platform code with his own platform-specific versions (plUUID vs pnUtUuid).

Almost all of the netcore and async stuff needs to be rewritten from scratch.

[branan]

the netcode is a disaster that needs to be rewritten. Maybe we can talk Chogon into sharing the UU netcode :P

[diafero]

Honestly UU was not much better, at least the protocol on the wire. Is it really necessary to have yet another network layer around plNetMsg? UU needed it to achieve reliable communication, but with TCP that need is gone.

[dpogue]

Given the states of the (not quite finished, but mostly working) macOS and Linux clients, I'm doing to mark this as done.