Add CITATION.cff and version in help usage

CITATION.cff

@@ -0,0 +1,18 @@
+cff-version: 1.2.0
+title: >-
+    Export tables from a MonetDB database for backups or exchanges
+message: Please cite this software as follows.
+type: software
+authors:
+  - given-names: Leon
+    family-names: Helwerda
+    email: [email protected]
+    affiliation: Leiden University
+    orcid: 'https://orcid.org/0000-0002-4299-466X'
+repository-code: 'https://github.com/grip-on-software/monetdb-dumper'
+url: 'https://gros.liacs.nl/'
+keywords:
+  - monetdb
+  - database-dumper
+license: Apache-2.0
+version: 0.0.3

src/databasedumper/Databasedumper.java

@@ -42,14 +42,15 @@
  * @author Leon Helwerda
  */
 public class Databasedumper {
+    private final static String VERSION = "0.0.3";
 
     /**
      * @param args the command line arguments
      */
     public static void main(String[] args) {
         String usage = "\nUsage: java -jar databasedumper.jar <table> <file>";
         if (args.length <= 1 || "--help".equals(args[0])) {
-            throw new DumperException(usage);
+            throw new DumperException(usage + "\nMonetDB dumper " + VERSION);
         }
         ResourceBundle bundle = ResourceBundle.getBundle("databasedumper.database");