Upgrades now easier to find on Joomlacode

[Tonie]

With Joomla 1.0.12, the full version of 1.0.12 and all upgrades were in one big list. This made it pretty hard to locate the full version. For 1.0.13 we split the full version and upgrades (http://joomlacode.org/gf/project/joomla/frs/), so it's easier for people to locate what they need. (I just made some changes, so it's also easy to find upgrades now)