(also added some more tabbing)

* mserv.c: added i_tcp.c's USE_WINSOCK macros so socklen_t isn't redundantly defined if Winsock 2 is used

i_tcp.c: SCOUW2 and SCOUW7 haven't been defined since we got rid of Doom Legacy's makefiles for UnixWare 2/7 (which are ANCIENT), so get rid of them!

added tabbing to some of the preprocessor code in i_tcp.c and mserv.c to make it easier to read them (and to allow me to understand what I need to do for the next commit)

If you ever need to, you can change the client port number.

Using strcpy is stupid because we don't know how long the argument would be.
There's no need for a buffer anyway.

Because IPv6 doesn't seem to work anyway.

Use temporary buffer with a max size of 255 bytes instead of having Microsoft's FormatMessageA alloc one for us. Also, provide a fallback message in case no message was available for some reason

Save the result of errno (aka WSAGetLastError() for WinSock) as soon as possible, to prevent anything in SOCK_GetNodeAddress resetting the value to 0 while trying to print the message for the error itself!

Creating a quick get_WSAErrorStr function to act as a wrapper for FormatMessageA so we can string-ify Winsock errors properly

Untested!

SOCK_Send: Split the actual sending data parts into a new function, SOCK_SendToAddr, to make everything look a bit neater in general

-Added a timeout for game state downloading to prevent definitive join freezes in some cases. The timeout has a minimum value of "jointimeout" and gets higher as the game state grows in size
-If the server tries to kick a joiner who is downloading the game state, they will get a timeout instead, because a regular kick would only happen once the game state has been downloaded
-Added a timeout for player ticcmd packets, again to prevent freezes to happen in some cases
-File/game state downloading is now faster, the speed is controlled by the "downloadspeed" cvar, in packets per tic
-The reason is now properly shown when the server refuses connection
-Changed the default values of "nettimeout" to 10 seconds (previously 15) and "maxsend" to 4 MB (previously 1)
-Added a "noticedownload" cvar that displays a message in the server console when someone is downloading a file