remove dependency of chown

Author: ygerlach

src/Utility/CronTab.vala

@@ -306,7 +306,7 @@ public class CronTab : GLib.Object {
 		}
 
 		file_write(file_path, sh);
-		chown(file_path, "root", "root");
+		Posix.chown(file_path, 0, 0); // chown to root:root
 		Posix.chmod(file_path, 0644);
 
 		log_msg(_("Added cron task") + ": %s".printf(file_path));

src/Utility/TeeJee.FileSystem.vala

@@ -414,12 +414,6 @@ namespace TeeJee.FileSystem{
 		return list;
 	}
 
-	public bool chown(string dir_path, string user, string group = user){
-		string cmd = "chown %s:%s -R '%s'".printf(user, group, escape_single_quote(dir_path));
-		int status = exec_sync(cmd, null, null);
-		return (status == 0);
-	}
-	
 	// misc --------------------
 
 	public string format_file_size (