TextField updates, and bug fixes from some recent commits.

- Added modified copy of slick.gui.TextField: added CTRL+BACKSPACE for word deletion, and disabled left/right arrows to move cursor and CTRL+Z to undo.
- Fixed musicEnded() incorrectly setting the "trackEnded" upon swapping tracks.  This has caused some nasty loops since #38.
- Fixed a null pointer exception in OsuDB from 0b03912.
- Fixed the song menu search bar transition being incorrectly reset when hitting backspace on a 0-length query.

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

src/itdelatrisu/opsu/db/OsuDB.java

@@ -76,12 +76,6 @@ public class OsuDB {
 		// create the database
 		createDatabase();
 
-		// retrieve the cache size
-		getCacheSize();
-
-		// check the database version
-		checkVersion();
-
 		// prepare sql statements
 		try {
 			insertStmt = connection.prepareStatement(
@@ -96,6 +90,12 @@ public class OsuDB {
 		} catch (SQLException e) {
 			ErrorHandler.error("Failed to prepare beatmap statements.", e, true);
 		}
+
+		// retrieve the cache size
+		getCacheSize();
+
+		// check the database version
+		checkVersion();
 	}
 
 	/**