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

test/net/http/isacceptablepath_test.c

@@ -23,10 +23,12 @@
 #include "net/http/http.h"
 
 TEST(IsAcceptablePath, test) {
+  EXPECT_TRUE(IsAcceptablePath("*", 1));
   EXPECT_TRUE(IsAcceptablePath("/", 1));
   EXPECT_TRUE(IsAcceptablePath("index.html", 10));
   EXPECT_TRUE(IsAcceptablePath("/index.html", 11));
   EXPECT_TRUE(IsAcceptablePath("/index.html", -1));
+  EXPECT_TRUE(IsAcceptablePath("/redbean.png", -1));
 }
 
 TEST(IsAcceptablePath, testEmptyString_allowedIfYouLikeImplicitLeadingSlash) {
@@ -88,5 +90,6 @@ TEST(IsAcceptablePath, testOverlongSlashDot_isDetected) {
 }
 
 BENCH(IsAcceptablePath, bench) {
+  EZBENCH2("IsAcceptablePath", donothing, IsAcceptablePath("*", 1));
   EZBENCH2("IsAcceptablePath", donothing, IsAcceptablePath("/index.html", 11));
 }