[WIP] Add batch names to claim codes

This allows admins to (optionally) assign names to the batches of claim codes that they generate. This will allow them to execute actions on specific batches, e.g. tracking statistics on them, printing them (see #184), deleting them, and so forth.

Here's an example of the claim code generation form with this PR merged:

![screen shot 2013-06-06 at 8 41 06 am](https://f.cloud.github.com/assets/124687/617913/846193c8-cea6-11e2-9158-a99eef5db697.png)