Pass overseer configuration over stdin

Summary:
Ref T7352. This changes `phd` to pass configuration to overseers over stdin. We still run one overseer per daemon.

The "status" stuff needs some cleanup, but it's mostly just UI/cosmetic.

Test Plan:
  - Ran `phd debug`, `phd launch`, `phd start`, `phd status`, `phd stop`, etc.
  - Verified PID files write in a reasonable format.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7352

Differential Revision: https://secure.phabricator.com/D11855

scripts/daemon/launch_daemon.php

@@ -8,20 +8,11 @@
 $root = dirname(dirname(dirname(__FILE__)));
 require_once $root.'/scripts/__init_script__.php';
 
-$flags = array();
+$overseer = new PhutilDaemonOverseer($argv);
 
 $bootloader = PhutilBootloader::getInstance();
 foreach ($bootloader->getAllLibraries() as $library) {
-  if ($library == 'phutil') {
-    // No need to load libphutil, it's necessarily loaded implicitly by the
-    // daemon itself.
-    continue;
-  }
-  $flags[] = '--load-phutil-library='.phutil_get_library_root($library);
+  $overseer->addLibrary(phutil_get_library_root($library));
 }
 
-// Add more flags.
-array_splice($argv, 2, 0, $flags);
-
-$overseer = new PhutilDaemonOverseer($argv);
 $overseer->run();