Add /statusz page to redbean plus other enhancements

redbean improvements:

- Explicitly disable corking
- Simulate Python regex API for Lua
- Send warmup requests in main process on startup
- Add Class-A granular IPv4 network classification
- Add /statusz page so you can monitor your redbean's health
- Fix regressions on OpenBSD/NetBSD caused by recent changes
- Plug Authorization header into Lua GetUser and GetPass APIs
- Recognize X-Forwarded-{For,Host} from local reverse proxies
- Add many additional functions to redbean Lua server page API
- Report resource usage of child processes on `/` listing page
- Introduce `-a` flag for logging child process resource usage
- Introduce `-t MILLIS` flag and `ProgramTimeout(ms)` init API
- Introduce `-H "Header: value"` flag and `ProgramHeader(k,v)` API

Cosmopolitan Libc improvements:

- Make strerror() simpler
- Make inet_pton() not depend on sscanf()
- Fix OpenExecutable() which broke .data section earlier
- Fix stdio in cases where it overflows kernel tty buffer
- Fix bugs in crash reporting w/o .com.dbg binary present
- Add polyfills for SO_LINGER, SO_RCVTIMEO, and SO_SNDTIMEO
- Polyfill TCP_CORK on BSD and XNU using TCP_NOPUSH magnums

New netcat clone in examples/nc.c:

While testing some of the failure conditions for redbean, I noticed that
BusyBox's `nc` command is pretty busted, if you use it as an interactive
tool, rather than having it be part of a pipeline. Unfortunately this'll
only work on UNIX since Windows doesn't let us poll on stdio and sockets
at the same time because I don't think they want tools like this running
on their platform. So if you want forbidden fruit, it's here so enjoy it

libc/sysv/consts/c.h

@@ -1,52 +1,25 @@
-#ifndef COSMOPOLITAN_LIBC_SYSV_CONSTS_C_H_
-#define COSMOPOLITAN_LIBC_SYSV_CONSTS_C_H_
-#include "libc/runtime/symbolic.h"
+#ifndef COSMOPOLITAN_LIBC_SYSV_CONSTS_CPIO_H_
+#define COSMOPOLITAN_LIBC_SYSV_CONSTS_CPIO_H_
 
-#define C_IRGRP SYMBOLIC(C_IRGRP)
-#define C_IROTH SYMBOLIC(C_IROTH)
-#define C_IRUSR SYMBOLIC(C_IRUSR)
-#define C_ISBLK SYMBOLIC(C_ISBLK)
-#define C_ISCHR SYMBOLIC(C_ISCHR)
-#define C_ISCTG SYMBOLIC(C_ISCTG)
-#define C_ISDIR SYMBOLIC(C_ISDIR)
-#define C_ISFIFO SYMBOLIC(C_ISFIFO)
-#define C_ISGID SYMBOLIC(C_ISGID)
-#define C_ISLNK SYMBOLIC(C_ISLNK)
-#define C_ISREG SYMBOLIC(C_ISREG)
-#define C_ISSOCK SYMBOLIC(C_ISSOCK)
-#define C_ISUID SYMBOLIC(C_ISUID)
-#define C_ISVTX SYMBOLIC(C_ISVTX)
-#define C_IWGRP SYMBOLIC(C_IWGRP)
-#define C_IWOTH SYMBOLIC(C_IWOTH)
-#define C_IWUSR SYMBOLIC(C_IWUSR)
-#define C_IXGRP SYMBOLIC(C_IXGRP)
-#define C_IXOTH SYMBOLIC(C_IXOTH)
-#define C_IXUSR SYMBOLIC(C_IXUSR)
+#define C_IXOTH  0000001
+#define C_IWOTH  0000002
+#define C_IROTH  0000004
+#define C_IXGRP  0000010
+#define C_IWGRP  0000020
+#define C_IRGRP  0000040
+#define C_IXUSR  0000100
+#define C_IWUSR  0000200
+#define C_IRUSR  0000400
+#define C_ISVTX  0001000
+#define C_ISGID  0002000
+#define C_ISUID  0004000
+#define C_ISFIFO 0010000
+#define C_ISCHR  0020000
+#define C_ISDIR  0040000
+#define C_ISBLK  0060000
+#define C_ISREG  0100000
+#define C_ISCTG  0110000
+#define C_ISLNK  0120000
+#define C_ISSOCK 0140000
 
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
-COSMOPOLITAN_C_START_
-
-extern const long C_IRGRP;
-extern const long C_IROTH;
-extern const long C_IRUSR;
-extern const long C_ISBLK;
-extern const long C_ISCHR;
-extern const long C_ISCTG;
-extern const long C_ISDIR;
-extern const long C_ISFIFO;
-extern const long C_ISGID;
-extern const long C_ISLNK;
-extern const long C_ISREG;
-extern const long C_ISSOCK;
-extern const long C_ISUID;
-extern const long C_ISVTX;
-extern const long C_IWGRP;
-extern const long C_IWOTH;
-extern const long C_IWUSR;
-extern const long C_IXGRP;
-extern const long C_IXOTH;
-extern const long C_IXUSR;
-
-COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_SYSV_CONSTS_C_H_ */
+#endif /* COSMOPOLITAN_LIBC_SYSV_CONSTS_CPIO_H_ */