Implements a backup to csv. Uses StringIO because it has an own writer()

method, which is pretty nice to have when csv.writer() want's that on its
passed variable.

Also respects every flag yet introduced(-c, -f, -a, -u) and reuses the code
already written in ListUsers.py. It could be very nice to bring that code
into lib/ because it is probably needed way more often

private/Backup.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+
+from lib.sqlitedb import SQLitedb
+import lib.CFG as CFG
+import ListUsers, csv, os, io
+
+if __name__ == "__main__":
+    try:
+        L = ListUsers.ListUsers()
+        fetch = L.getFetch()
+        ret = io.StringIO()
+        writer = csv.writer(ret, quoting=csv.QUOTE_NONNUMERIC) # @TODO: Should be a specific dialect instead?
+        writer.writerow(['id', 'username', 'email', 'name', 'pubkey' 'timestamp', 'status'])
+        for user in fetch:
+            writer.writerow([user['id'], user['username'], user['email'], user['name'], user['pubkey'],
+                            user['timestamp'], user['status']])
+
+        if CFG.args.file == "stdout":
+            print(ret.getvalue())
+        else:
+            with open(CFG.args.file, "w") as f:
+                print(ret.getvalue(), file=f)
+        exit(0)
+    except KeyboardInterrupt as e:
+        pass