Windows support: portable local server launch + clean quit, %APPDATA% data dir, Win32 libs, MinGW/MSVC build docs

client/App.h

@@ -3,6 +3,7 @@
 // creator, play) and the glue between NetClient, World and the HD-2D UI.
 
 #include "Common.h"
+#include "LocalServer.h"
 #include "NetClient.h"
 #include "World.h"
 
@@ -111,7 +112,7 @@ private:
     std::vector<net::ServerInfo> found_;
     float scanTimer_ = 0.0f;
     char addressBuf_[128] = "127.0.0.1";
-    int serverPid_ = -1;
+    LocalServer localServer_;
     float connectTimer_ = 0.0f;
 
     // creator