Release pledge.com 1.7 and landlockmake.com 1.3

- pledge("chown") now supported
- pledge("stdio") now allows killing self
- Write tests for pselect() and ppoll()

libc/calls/pledge.c

@@ -30,6 +30,7 @@
 /**
  * Permits system operations, e.g.
  *
+ *     __pledge_mode = PLEDGE_PENALTY_KILL_PROCESS | PLEDGE_STDERR_LOGGING;
  *     if (pledge("stdio rfile tty", 0)) {
  *       perror("pledge");
  *       exit(1);