daemon: added daemonize_init(), daemonize_finish()

The constructor/destructor functions parse and free the configuration
properly.  This way, we don't have to load the pid file path more than
once.

src/daemon.h

@@ -21,6 +21,12 @@
 
 #include "cmdline.h"
 
+void
+daemonize_init(const char *user, const char *pidfile);
+
+void
+daemonize_finish(void);
+
 /**
  * Kill the MPD which is currently running, pid determined from the
  * pid file.
@@ -43,10 +49,4 @@ daemonize_set_user(void);
 void
 daemonize(Options *options);
 
-/**
- * Deletes the pidfile which was created when MPD started.
- */
-void
-daemonize_delete_pidfile(void);
-
 #endif