Remove chznSpritePath; prefer in parent file

What's the preferred method of integrating bootstrap-chosen?

One method is as "read-only" vendor code: bootstrap-chosen gets included in a
parent file (see the following). However, requires the chznSpritePath
declaration to be in the parent scope due to less's [scoping rules][1].

  [1]: http://stackoverflow.com/q/12928246

```
$ tree assets
assets
|-- img
|   `-- vendor
|       `-- chosen
|           `-- chosen-sprite.png
`-- less
    |-- bootstrap-chosen.less
    `-- vendor
        |-- bootstrap
            `-- ...
        `-- bootstrap-chosen
            |-- bootstrap-chosen.less
            |-- example.html
            |-- example.png
            `-- README.md

$ cat assets/less/bootstrap-chosen.less

// Import bootstrap-chosen's Boostrap dependencies
@import "vendor/bootstrap/less/variables.less";
@import "vendor/bootstrap/less/mixins.less";

@chznSpritePath: "../img/vendor/chosen/chosen-sprite.png";
@import "vendor/bootstrap-chosen/bootstrap-chosen.less";
```

Alternatively, could you just include `chosen-sprite.png` in the project
(chosen is MIT licensed)?