#472 Recovery code: allow to configure length, expiration and email

src/main/resources/config.yml

@@ -342,6 +342,11 @@ Security:
         # How many minutes before resetting the count for failed logins by IP and username
         # Default: 480 minutes (8 hours)
         minutesBeforeCounterReset: 480
+    recoveryCode:
+        # Number of characters a recovery code should have
+        length: 8
+        # How many hours is a recovery code valid for?
+        validForHours: 4
 Converter:
     Rakamak:
         # Rakamak file name

src/main/resources/recovery_code_email.html

@@ -0,0 +1,9 @@
+<h1>Dear <playername />,</h1>
+
+<p>
+    You have requested to reset your password on <servername />. To reset it,
+    please use the recovery code <recoverycode />: /email recover [email] <recoverycode />.
+</p>
+<p>
+    The code expires in <hoursvalid /> hours.
+</p>