Change password task to async process

- Perform async change password task just like other async processes: via Management
- Remove legacy setting
- Remove now unused service getter (#736)

src/main/java/fr/xephi/authme/process/Management.java

@@ -1,5 +1,6 @@
 package fr.xephi.authme.process;
 
+import fr.xephi.authme.process.changepassword.AsyncChangePassword;
 import fr.xephi.authme.process.email.AsyncAddEmail;
 import fr.xephi.authme.process.email.AsyncChangeEmail;
 import fr.xephi.authme.process.join.AsynchronousJoin;
@@ -36,9 +37,12 @@ public class Management {
     private AsynchronousLogin asynchronousLogin;
     @Inject
     private AsynchronousUnregister asynchronousUnregister;
+    @Inject
+    private AsyncChangePassword asyncChangePassword;
 
     Management() { }
 
+
     public void performLogin(final Player player, final String password, final boolean forceLogin) {
         runTask(new Runnable() {
             @Override
@@ -111,6 +115,15 @@ public class Management {
         });
     }
 
+    public void performPasswordChange(final Player player, final String oldPassword, final String newPassword) {
+        runTask(new Runnable() {
+            @Override
+            public void run() {
+                asyncChangePassword.changePassword(player, oldPassword, newPassword);
+            }
+        });
+    }
+
     private void runTask(Runnable runnable) {
         bukkitService.runTaskAsynchronously(runnable);
     }