Add method to deserialize the custom map

src/main/java/com/massivecraft/factions/util/PermissionsMapTypeAdapter.java

@@ -0,0 +1,51 @@
+package com.massivecraft.factions.util;
+
+import com.google.gson.*;
+import com.massivecraft.factions.P;
+import com.massivecraft.factions.struct.Relation;
+import com.massivecraft.factions.zcore.fperms.Access;
+import com.massivecraft.factions.zcore.fperms.Action;
+
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.logging.Level;
+
+public class PermissionsMapTypeAdapter implements JsonDeserializer<Map<Relation, Map<Action, Access>>> {
+
+    @Override
+    public Map<Relation, Map<Action, Access>> deserialize(JsonElement json, Type type, JsonDeserializationContext context) throws JsonParseException {
+
+        try {
+            JsonObject obj = json.getAsJsonObject();
+            if (obj == null) {
+                return null;
+            }
+
+            Map<Relation, Map<Action, Access>> permissionsMap = new ConcurrentHashMap<>();
+
+            // Top level is Relation
+            for (Map.Entry<String, JsonElement> entry : obj.entrySet()) {
+                Relation relation = Relation.fromString(entry.getKey());
+
+                // Second level is the map between action -> access
+                for (Map.Entry<String, JsonElement> entry2 : entry.getValue().getAsJsonObject().entrySet()) {
+                    Map<Action, Access> accessMap = new HashMap<>();
+                    Action action = Action.fromString(entry2.getKey());
+                    Access access = Access.fromString(entry2.getValue().getAsString());
+                    accessMap.put(action, access);
+
+                    permissionsMap.put(relation, accessMap);
+                }
+            }
+
+            return permissionsMap;
+
+        } catch (Exception ex) {
+            ex.printStackTrace();
+            P.p.log(Level.WARNING, "Error encountered while deserializing a Map of FLocations to String Sets.");
+            return null;
+        }
+    }
+}