Make copy for version downloads clearer

:fork_and_knife: We currently display the number of downloads for the current version being viewed so we should make the copy more clear to convey that. Know looks like:

![screen shot 2014-07-22 at 3 09 33 pm](https://cloud.githubusercontent.com/assets/316507/3663509/c6ccf29a-11d3-11e4-8306-8fe389462f14.png)