change default Java version regex

Closes #93

src/main/java/com/threerings/getdown/data/Application.java

@@ -1882,7 +1882,7 @@ public class Application
     protected int _trackingId;
 
     protected String _javaVersionProp = "java.version";
-    protected String _javaVersionRegex = "(\\d+)\\.(\\d+)\\.(\\d+)(_\\d+)?.*";
+    protected String _javaVersionRegex = "(\\d+)(?:\\.(\\d+)(?:\\.(\\d+)(_\\d+)?)?)?";
     protected long _javaMinVersion, _javaMaxVersion;
     protected boolean _javaExactVersionRequired;
     protected String _javaLocation;