Make improvements

- Expand redbean UNIX module
- Expand redbean documentation
- Ensure Lua copyright is embedded in binary
- Increase the PATH_MAX limit especially on NT
- Use column major sorting for linenoise completions
- Fix some suboptimalities in redbean's new UNIX API
- Figured out right flags for Multics newline in raw mode

third_party/lua/lrepl.h

@@ -1,14 +1,29 @@
 #ifndef COSMOPOLITAN_THIRD_PARTY_LUA_LREPL_H_
 #define COSMOPOLITAN_THIRD_PARTY_LUA_LREPL_H_
+#include "libc/dce.h"
+#include "libc/intrin/spinlock.h"
 #include "third_party/linenoise/linenoise.h"
 #include "third_party/lua/lauxlib.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
-extern char lualock;
+#if !defined(STATIC) && SupportsWindows()
+#define LUA_REPL_LOCK _spinlock(&lua_repl_lock)
+#else
+#define LUA_REPL_LOCK (void)0
+#endif
+
+#if !defined(STATIC) && SupportsWindows()
+#define LUA_REPL_UNLOCK _spunlock(&lua_repl_lock)
+#else
+#define LUA_REPL_UNLOCK (void)0
+#endif
+
+extern char lua_repl_lock;
 extern bool lua_repl_blocking;
 extern bool lua_repl_isterminal;
 extern struct linenoiseState *lua_repl_linenoise;
+extern linenoiseCompletionCallback *lua_repl_completions_callback;
 
 void lua_freerepl(void);
 int lua_loadline(lua_State *);