LPS-38029 Display a progress bar with the status of a process (export, import, publish)

Hey @natecavanaugh, we only need you to have a look at the html used to generated the progress bar and the css.

see screenshot attached. You will need files bigger than 200 Mb in the DL in order to be able to see it in action.

thanks!

![screenshot_17_07_13_14_18](https://f.cloud.github.com/assets/203395/841774/360e64fe-f39e-11e2-9a31-35077e9b61aa.png)