Added a beatmap cache database.

- New database ".opsu.db" stores a cached copy of all parsed beatmaps.  All data will be read from this database unless the last modified time of a beatmap file does not match the one in the table.
- OsuParser inserts all new entries to the database in batch after parsing.
- Added *toString()/*fromString() methods for 'breaks', 'timingPoints', and 'combo' fields in OsuFile for use with the database.
- For any database format changes, update the DATABASE_VERSION field in OsuDB.
- Reloading beatmaps (F5) will now clear the beatmap cache.

Related changes:
- Added small DBController class for convenience.
- Changed 'bg' field of OsuFile to only contain the image file name, instead of the full path.
- Deleted printDatabase() method from ScoreDB.

Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>

src/itdelatrisu/opsu/db/DBController.java

@@ -0,0 +1,53 @@
+/*
+ * opsu! - an open-source osu! client
+ * Copyright (C) 2014, 2015 Jeffrey Han
+ *
+ * opsu! 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.
+ *
+ * opsu! 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 opsu!.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package itdelatrisu.opsu.db;
+
+import itdelatrisu.opsu.ErrorHandler;
+
+/**
+ * Database controller.
+ */
+public class DBController {
+	// This class should not be instantiated.
+	private DBController() {}
+
+	/**
+	 * Initializes all databases.
+	 */
+	public static void init() {
+		// load the sqlite-JDBC driver using the current class loader
+		try {
+			Class.forName("org.sqlite.JDBC");
+		} catch (ClassNotFoundException e) {
+			ErrorHandler.error("Could not load sqlite-JDBC driver.", e, true);
+		}
+
+		// initialize the databases
+		OsuDB.init();
+		ScoreDB.init();
+	}
+
+	/**
+	 * Closes all database connections.
+	 */
+	public static void closeConnections() {
+		OsuDB.closeConnection();
+		ScoreDB.closeConnection();
+	}
+}