Modularizes the Maven project

This commit modularizes the maven project into several modules:
 - l2jserver2-common: common sources for both login and gameserver
 - l2jserver2-gameserver: the game server
 - l2jserver2-loginserver: the login server
 - l2jserver2-tools: refactored src/tools/java soure folder

l2jserver2-common/src/main/java/com/l2jserver/service/cache/Cache.java

@@ -0,0 +1,73 @@
+/*
+ * This file is part of l2jserver <l2jserver.com>.
+ *
+ * l2jserver 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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * l2jserver 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 l2jserver.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.l2jserver.service.cache;
+
+/**
+ * This interface represents a Map structure for cache usage.
+ * 
+ * @author <a href="http://www.rogiel.com">Rogiel</a>
+ * @param <K>
+ *            the key type
+ * @param <V>
+ *            the value type
+ */
+public interface Cache<K, V> extends Iterable<V> {
+	/**
+	 * Adds a pair <key,value> to cache.<br>
+	 * <br>
+	 * 
+	 * <font color='red'><b>NOTICE:</b> </font> if there is already a value with
+	 * given id in the map, {@link IllegalArgumentException} will be thrown.
+	 * 
+	 * @param key
+	 *            the key name
+	 * @param value
+	 *            the cache content value
+	 */
+	void put(K key, V value);
+
+	/**
+	 * Returns cached value correlated to given key.
+	 * 
+	 * @param key
+	 *            the key
+	 * @return the cached value for this key
+	 */
+	V get(K key);
+
+	/**
+	 * Checks whether this map contains a value related to given key.
+	 * 
+	 * @param key
+	 *            the key
+	 * @return true if key has an value
+	 */
+	boolean contains(K key);
+
+	/**
+	 * Removes an entry from the map, that has given key.
+	 * 
+	 * @param key
+	 *            the key
+	 */
+	void remove(K key);
+
+	/**
+	 * Clears this cache
+	 */
+	void clear();
+}