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

README.md

@@ -16,7 +16,7 @@ Sometime in 2006 or 2007, I abandoned khyller and rebuilt the entire thing from
 
 A little-known fact is that no version of khyller or newserv was ever tested with the DreamCast versions of PSO. Both projects claimed to support them, but the DC server implementations were based only on chat conversations (likely now lost to time) with other people in the community who had done research on the DC version.
 
-Last weekend (October 2018), I had some random cause to reminisce. I looked back in my old code archives and came across newserv. Somehow inspired, I spent a weekend and a couple more evenings rewriting the entire project again, cleaning up ancient patterns I had used eleven years ago, replacing entire modules with simple STL containers, and eliminating even more support files in favor of configuration autodetection. The code is now suitably modern and the concurrency primitives it uses are correct (thought I haven't audited where exactly they're used; there are likely some missing lock contexts still).
+Sometime in October 2018, I had some random cause to reminisce. I looked back in my old code archives and came across newserv. Somehow inspired, I spent a weekend and a couple more evenings rewriting the entire project again, cleaning up ancient patterns I had used eleven years ago, replacing entire modules with simple STL containers, and eliminating even more support files in favor of configuration autodetection. The code is now suitably modern and it no longer has insidious concurrency bugs because it's no longer concurrent - the server is now entirely event-driven.
 
 ## Future
 
@@ -27,7 +27,7 @@ This project is primarily for my own nostalgia. Feel free to peruse if you'd lik
 Currently this code should build on macOS and Ubuntu. It might build on other Linux flavors, but don't expect it to work on Windows at all.
 
 So, you've read all of the above and you want to try it out? Here's what you do:
-- Make sure you have libreadline and libevent installed (use Homebrew in macOS, or install libreadline-dev and libevent-dev in Linux).
+- Make sure you have libevent installed (use Homebrew in macOS, or install libevent-dev in Linux).
 - Build and install phosg (https://github.com/fuzziqersoftware/phosg).
 - Run `make`.
 - Edit system/config.json to your liking.