text: Title: Wrong behavior in compressed version
  Body: I'm testing `django-jet` as `OpenEdx`'s admin theme and i have the correct behaviour in `LMS` section:
  ![seleccion_018](https://cloud.githubusercontent.com/assets/5034215/26670642/0fb4a9fc-46bb-11e7-9df2-c5eb5f758578.png)
  It works perfectly in `Opera - Chromiun` and `Firefox`, and, very important, as you can see, all static files isn't compressed.
  
  But in `Studio / CMS` the history is very different:
  ![seleccion_016](https://cloud.githubusercontent.com/assets/5034215/26670634/0867bf36-46bb-11e7-996f-fdddf1b345f1.png)
  The styles are a melty of normal `Django` admin and `Jet` and make very ugly effects:
  - Pinned button right padding is wrong.
  - Header / Breadcrumbs section with normal styles.
  - User button and menu dissapeared.
  - Wrong `svg` icons rendering.
  And others.
  As you can see this site use compressor for compress the files.
  
  ![seleccion_017](https://cloud.githubusercontent.com/assets/5034215/26670637/0c04c6c0-46bb-11e7-8c14-20b9786e7ed5.png)
  So, i proceeded to delete the base admin style and i got a "perfect" behaviour, but i know this is not properly solution.
  
  In `Firefox` the problem is not uglier than `Opera - Chromiun` but exist also:
  ![seleccion_020](https://cloud.githubusercontent.com/assets/5034215/26670646/1534f2a6-46bb-11e7-80db-2a4745bae785.png)
  As you can see, again, title section in menu doesn't appear and the user name button with menu also.
  ![seleccion_023](https://cloud.githubusercontent.com/assets/5034215/26670648/18def38e-46bb-11e7-9968-e3b6cb14b566.png)
  Deleting the same line of code (`admin-base`) the theme works "perfectly".
  
  So, i think as conclusion that for any reason `Jet` styles are conflicting with normal styles with both are compressed.
  
  Why happen this?
  
  Additional information here:
  ![seleccion_024](https://cloud.githubusercontent.com/assets/5034215/26671448/3690394e-46be-11e7-9dc3-9a1183c85a7e.png)
  