Make improvements

- Add rusage to redbean Lua API
- Add more redbean documentation
- Add pledge() to redbean Lua API
- Polyfill OpenBSD pledge() for Linux
- Increase PATH_MAX limit to 1024 characters
- Untrack sibling processes after fork() on Windows

libc/runtime/runtime.h

@@ -104,6 +104,7 @@ char *GetProgramExecutableName(void);
 char *GetInterpreterExecutableName(char *, size_t);
 void __printargs(const char *);
 void __paginate(int, const char *);
+int __arg_max(void);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */