Remove cache, add disable-offline-access config node

Fixes various permissions not being respected during login/logout with inventories already open. This will result in a performance hit for repeated open/closes - there will be significantly more disk I/O.

Closes lishid#171
Closes #56

plugin/src/main/java/com/lishid/openinv/OfflineHandler.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2011-2022 lishid. All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.lishid.openinv;
+
+import com.lishid.openinv.internal.ISpecialInventory;
+import com.lishid.openinv.util.Permissions;
+import java.util.Map;
+import java.util.UUID;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import org.jetbrains.annotations.NotNull;
+
+record OfflineHandler(
+        @NotNull BiFunction<Map<UUID, ? extends ISpecialInventory>, UUID, ISpecialInventory> fetch,
+        @NotNull Consumer<@NotNull ISpecialInventory> handle) {
+
+    static final OfflineHandler REMOVE_AND_CLOSE = new OfflineHandler(
+            Map::remove,
+            inventory -> OpenInv.ejectViewers(inventory, viewer -> true)
+    );
+
+    static final OfflineHandler REQUIRE_PERMISSIONS = new OfflineHandler(
+            Map::get,
+            inventory -> OpenInv.ejectViewers(inventory, viewer -> !Permissions.OPENOFFLINE.hasPermission(viewer))
+    );
+
+}