Support option strings for combo fields

For #1259 and #1709
Now combo fields can support a strings object instead of just displaying the keys.  This allows for friendlier (and translatable!) values.

I did not add strings for every preset with a combo field, but I did convert many of the most useful ones in 98119b5.

![screenshot 2014-07-21 16 29 36](https://cloud.githubusercontent.com/assets/38784/3649880/9f41e842-1116-11e4-916d-0b237f27ab49.png)
![screenshot 2014-07-21 16 29 18](https://cloud.githubusercontent.com/assets/38784/3649883/a1249b82-1116-11e4-8f4e-bf3956ae1b14.png)

This is the thing I'm most unsure about too.  We can't let users edit the localized strings, but we also shouldn't force them into the raw tag editor if they want to add a value not in the list.

I'm considering implementing 2 features like this:

```
    "strings": {
        "allowOther": true,
        "loadMore": true,
        "options": {
            "christian": "Christian",
            "muslim": "Muslim",
            "buddhist": "Buddhist",
            "jewish": "Jewish",
            "hindu": "Hindu",
            "shinto": "Shinto",
            "taoist": "Taoist"
        }
    }
```

`allowOther` (default false) would add an "Other..." value to the dropdown, which if selected would unlock the field and let the user type their own value (preserving current behavior). For lists where we expect the user to sometimes supply their own value.

`loadMore` (default false) would tell the combo to pull the top 25 values from tagInfo, but display the matching stringified ones first.  For lists that we know will never be 100%.