Implemented the setspawn command

src/main/java/fr/xephi/authme/command/CommandManager.java

@@ -195,6 +195,18 @@ public class CommandManager {
         setEmailCommand.addArgument(new CommandArgumentDescription("player", "Player name", false));
         setEmailCommand.addArgument(new CommandArgumentDescription("email", "Player email", false));
 
+        // Register the setspawn command
+        CommandDescription setSpawnCommand = new CommandDescription(
+                new SetSpawnCommand(),
+                new ArrayList<String>() {{
+                    add("setspawn");
+                    add("chgspawn");
+                }},
+                "Change the spawn",
+                "Change the player's spawn to your current position.",
+                authMeCommand);
+        setSpawnCommand.setCommandPermissions("authme.admin.setspawn", CommandPermissions.DefaultPermission.OP_ONLY);
+
         // Register the purge command
         CommandDescription purgeCommand = new CommandDescription(
                 new PurgeCommand(),

src/main/java/fr/xephi/authme/command/executable/authme/SetSpawnCommand.java

@@ -0,0 +1,39 @@
+package fr.xephi.authme.command.executable.authme;
+
+import fr.xephi.authme.ConsoleLogger;
+import fr.xephi.authme.command.CommandParts;
+import fr.xephi.authme.command.ExecutableCommand;
+import fr.xephi.authme.settings.Spawn;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+
+public class SetSpawnCommand extends ExecutableCommand {
+
+    /**
+     * Execute the command.
+     *
+     * @param sender           The command sender.
+     * @param commandReference The command reference.
+     * @param commandArguments The command arguments.
+     *
+     * @return True if the command was executed successfully, false otherwise.
+     */
+    @Override
+    public boolean executeCommand(CommandSender sender, CommandParts commandReference, CommandParts commandArguments) {
+        // Make sure the command executor is a player
+        try {
+            if (sender instanceof Player) {
+                if (Spawn.getInstance().setSpawn(((Player) sender).getLocation())) {
+                    sender.sendMessage("[AuthMe] Correctly defined new spawn point");
+                } else {
+                    sender.sendMessage("[AuthMe] SetSpawn has failed, please retry");
+                }
+            } else {
+                sender.sendMessage("[AuthMe] Please use that command in game");
+            }
+        } catch (NullPointerException ex) {
+            ConsoleLogger.showError(ex.getMessage());
+        }
+        return true;
+    }
+}