Bug 821016: Update new-b page JS virtual URL for more info.

* increase download URL timeout to catch more conversions.
* update ga snippet to use debug ga.js if TEMPLATE_DEBUG is True.

Fix bug 830083.
Merge pull request #591 from pmclanahan/bug-821016-update-new-b-ga-virtual-url

Bug 821016: Update new-b page JS virtual URL for more info.