Add a delay when clicking download button.

[Bug #930131](https://bugzilla.mozilla.org/show_bug.cgi?id=930131)

Delay is needed to allow animation to complete in IE9/10.
Fix bug 931042: Redirect /collusion/ to /lightbeam/.

Remove collusion related assets.
Merge pull request #1335 from gauthierm/bug-930131-fix-preloading

Bug 930131: Add a delay when clicking download button.
Merge pull request #1343 from pmclanahan/redirect-collusion-lightbeam-931042

Fix bug 931042: Redirect /collusion/ to /lightbeam/.