fix a lot of issues on psogc; add proxy module

- $ann implemented
- concurrency removed; server is now single-threaded, event-driven and much more stable
- rare seed is no longer the game id; ids are sequential from server startup so they weren't random at all before
- supports dropping privileges; now you can run it as root so it can open a sockets on low ports, then it will switch to the given user before serving any traffic
- newserv now behaves like a proxy if you run it with the --proxy-destination=<IP_OR_HOSTNAME> argument; there's also an (invisible) shell in this mode where you can inject commands to the server or client. e.g. it can always be christmas in the lobby if you do `sc DA 01 00 00`
- increased the mtu on PSODolphinConfig's tap0 configuration; this seems to make the connection more stable
- fixed some uninitialized memory bugs
- the shell is now event-driven and now uses libevent too; unfortunately this means readline doesn't work anymore (no history and vim-like shortcuts)
- made network command display consistent for input vs. output (the header appears in both cases now)
- fixed bugs in some subcommand handling (the BB logic was being applied to non-BB clients erroneously, causing most item drops not to work at all)
- fixed player tags in the short lobby data struct. unclear if this was actually a problem but it was inconsistent with other servers
- fixed "unused" field in game join command (actually it appears to be disable_udp and should be 1, not 0)
- cleaned up Server abstraction a bit
- rewrote some text functions; asan was complaining about the built-in ones for some reason
- added an optional welcome message

system/config.json

@@ -7,15 +7,18 @@
   "LocalAddress": "192.168.0.5",
   // Address to connect external clients to
   "ExternalAddress": "10.0.1.6",
-  // Number of worker threads to run. If zero, use as many threads as there are
-  // CPU cores.
-  "Threads": 0,
   // Set to false to disable the DNS server
   "RunDNSServer": true,
   // By default, the interactive shell runs if stdin is a terminal, and doesn't
   // run if it's not. This option, if present, overrides that behavior.
   // "RunInteractiveShell": false,
 
+  // User to run the server as. If present, newserv will attempt to switch to
+  // this user's permissions after loading its configuration and opening
+  // listening sockets. The special value $SUDO_USER causes newserv to look up
+  // the desired username in the $SUDO_USER variable instead.
+  "User": "$SUDO_USER",
+
   // Information menu contents. Each entry is a 3-list of
   // [title, short description, full contents]. In the short description and
   // full contents, you can use PSO escape codes with the $ character (for
@@ -38,6 +41,9 @@
     ["Ep3 lobby types", "$C7Display lobby type\nlist for Episode\nIII", "These values can be used with the %sln command.\n$C6*$C7 indicates lobbies where players can't move.\n$C8Pink$C7 indicates Episode 3 only lobbies.\n\nnormal - standard lobby\n$C8planet$C7 - Blank Ragol Lobby\n$C8clouds$C7 - Blank Sky Lobby\n$C8cave$C7 - Unguis Lapis\n$C8jungle$C7 - Episode 2 Jungle\n$C8forest2-1$C7 - Episode 1 Forest 2 (ground)\n$C8forest2-2$C7 - Episode 1 Forest 2 (near Dome)\n$C8windpower$C7\n$C8overview$C7\n$C8seaside$C7 - Episode 2 Seaside\n$C8some?$C7\n$C8dmorgue$C7 - Destroyed Morgue\n$C8caelum$C7 - Caelum\n$C8digital$C7\n$C8boss1$C7\n$C8boss2$C7\n$C8boss3$C7\n$C8knight$C7 - Leukon Knight stage\n$C8sky$C7 - Via Tubus\n$C8morgue$C7 - Morgue"],
     ["Area list",       "$C7Display stage code\nlist", "These values can be used with the $C6%swarp$C7 command.\n\n$C2Green$C7 areas will be empty unless you are in a quest.\n$C6Yellow$C7 areas will not allow you to move.\n\n   $C8Episode 1  / Episode 2        / Episode 4$C7\n0: Pioneer 2  / Pioneer 2        / Pioneer 2\n1: Forest 1   / Temple Alpha    / Crater East\n2: Forest 2   / Temple Beta     / Crater West\n3: Caves 1    / Spaceship Alpha / Crater South\n4: Caves 2    / Spaceship Beta  / Crater North\n5: Caves 3    / CCA              / Crater Interior\n6: Mines 1    / Jungle North     / Desert 1\n7: Mines 2    / Jungle South     / Desert 2\n8: Ruins 1     / Mountain         / Desert 3\n9: Ruins 2     / Seaside          / Saint Million\n10: Ruins 3   / Seabed Upper    / $C6Purgatory$C7\n11: Dragon    / Seabed Lower\n12: De Rol Le / Gal Gryphon\n13: Vol Opt   / Olga Flow\n14: Dark Falz / Barba Ray\n15: $C2Lobby$C7     / Gol Dragon\n16: $C6Battle 1$C7  / $C6Seaside Night$C7\n17: $C6Battle 2$C7  / $C2Tower$C7"],
   ],
+  // Welcome message. If not blank, this message will be shown to console users
+  // upon first connecting.
+  "WelcomeMessage": "Welcome to $C6Alexandria$C7, a private PSO server\npowered by newserv.",
 
   // Item drop rates for non-rare items. For each type (boxes or enemies), all
   // the categories must add up to a number less than 0x100000000. Each number