pull changes from master to dev on 2014-12-24

This update brings these approved pulls to the dev branch:
* User-visible:
    * #1466: fix "invalid speed attack" messages to show the right messages for invalid berserk attacks
    * #1470: fix internal error related to asymmetric twin dice by tracking information about twin subdice and adding it to the API
    * #1461: more buttons, including playable versions of several of the Las Vegas buttons, and a couple of rare promos and others

Database updates:
```
01329j_incomplete_sets.sql
```

Once this pull is merged, i will load the changes on dev.buttonweavers.com as part of #217.