Room and lobby chat, /host, /fashion, player-colored lines, context tips, and American spelling

- Chat goes to your room (the sandbox, or your game) by default, and to the whole lobby with /all or a leading !.
  Lines from elsewhere say where they came from ([Sandbox], [Game 2]), lobby-wide ones from your room say [All].
  Typing shows only to your room. Protocol 8.
- Hosting: everyone is told who hosts now, and the host can hand it over with /host "player".
- /fashion <item> wears a fashion locally, like /color.
- Lines that mention a player show in that player's color, looked up as they draw.
- Tips are tagged with the item and situations they fit, and those that fit are 1.5x as likely. They turn over every
  10 seconds on one continuous run, show under the menu too, and can be turned off with Tips in HUD / Gameplay. The
  HUD hotbars hide while the menu is up (except on its item tabs).
- American spelling throughout: color, center, gray, mustache, and so on.

CMakeLists.txt

@@ -6,7 +6,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 # The simulation must run identically on every platform (desktop and web play together), so floating point is kept
-# strict: no fusing multiplies and adds (GCC and arm64 Clang do by default), no fast-math reordering. The maths
+# strict: no fusing multiplies and adds (GCC and arm64 Clang do by default), no fast-math reordering. The math
 # library's transcendentals are replaced by src/dmath.h.
 if(MSVC)
     add_compile_options(/fp:precise /fp:contract-)