huntd(6): convert malloc(x * y) and realloc(x * y) to reallocarr

I wish the socket API didn't require casts. Easy to mess them up.

Tidy up list of broadcast addresses.

Clean up the handling of the list of hunt daemons.

more cleanup

unexpose some globals that server.c previously required

name reform, fewer file statics

goto considered harmful

split off a bunch of the nastier network code into its own file