Should have way of passing variable data from conf to test runner

There should be a way to share things like dynamic configurations (things that can't be shared via static files) to test runner. Or even configs that are parsed via node.js and normally passed to browser with require.js define() call.

``` js
define('config', { thing1: 'somevalue' });
```

where the content of that object comes from node.js parsing different files to one object (fe. certain pieces of the server configuration that are exposed to clientside etc.).

Would it be possible fe. in `karma.conf.js` to have strings in files array with some special object, as directly having the file content?

``` js
files: [
{ content: "define('config', { thing1: 'somevalue' });" }
]
```

This would not need new fields for passing data and would probably be the most flexible solution.

Start by tracing how karma.conf.js is parsed and how the files array is handled by the test runner. Determine how dynamically generated content could be represented alongside file paths, then define tests showing that an object with content is injected and that existing static file entries continue to work.

Written by the indexing model from the issue text.