#1073 Add delay to email recovery command

- Add configurable cooldown period after sending an email for /email recovery
- Change ExpiringMap to remove expired entries (like ExpiringSet)
- Create method to translate durations via the messages file

src/main/java/fr/xephi/authme/util/Utils.java

@@ -3,7 +3,6 @@ package fr.xephi.authme.util;
 import fr.xephi.authme.ConsoleLogger;
 
 import java.util.Collection;
-import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 
 /**
@@ -71,36 +70,4 @@ public final class Utils {
         return Runtime.getRuntime().availableProcessors();
     }
 
-    public static Duration convertMillisToSuitableUnit(long duration) {
-        TimeUnit targetUnit;
-        if (duration > 1000L * 60L * 60L * 24L) {
-            targetUnit = TimeUnit.DAYS;
-        } else if (duration > 1000L * 60L * 60L) {
-            targetUnit = TimeUnit.HOURS;
-        } else if (duration > 1000L * 60L) {
-            targetUnit = TimeUnit.MINUTES;
-        } else if (duration > 1000L) {
-            targetUnit = TimeUnit.SECONDS;
-        } else {
-            targetUnit = TimeUnit.MILLISECONDS;
-        }
-
-        return new Duration(targetUnit, duration);
-    }
-
-    public static final class Duration {
-
-        private final long duration;
-        private final TimeUnit unit;
-
-        Duration(TimeUnit targetUnit, long durationMillis) {
-            this(targetUnit, durationMillis, TimeUnit.MILLISECONDS);
-        }
-
-        Duration(TimeUnit targetUnit, long sourceDuration, TimeUnit sourceUnit) {
-            this.duration = targetUnit.convert(sourceDuration, sourceUnit);
-            this.unit = targetUnit;
-        }
-    }
-
 }