Consider grouping versions

[philwebb]

The version selector pop-up currently lists all available versions:

I think for many users, they are likely to want the one of the following options (in this order):

1. To select an older stable release
2. To try a recent milestone
3. To try a snapshot

If we grouped releases by category and hid snapshots by default it might make the list easier to navigate.

Here's a mock up: