Prevent environment indicator from occasionally wrapping

Occasionally the browser would render the environment indicator on a new line. A refresh would sometimes fix, sometimes not even though the code was unchanged.

* Attempt to fix (the rendering bug isn't easily reproducible) by removing floats and the associated float calculations from the render tree
* Mark indicator as inline-block and include inline-block IE7 hack
* Reposition crown background in IE7

(IE7 is currently 2% of admin app sessions)

## Example of the bug
![screen shot 2014-12-04 at 16 41 38](https://cloud.githubusercontent.com/assets/319055/5301921/783589e2-7bd4-11e4-8fdb-933666be46c8.png)

cc @benilovj