convert 1.6 themes to 1.8

[TBO29]

I found that the easiest (some sort of) way of adapting my 1.6 theme to 1.8 is to make the modifications directly on the 1.8 theme and changing, adding or modifying the css parts where needed.

I also already ported almost all plugins I'm using to 1.8 and only need the most important like myalerts. mentionme and Google Seo which I hope the programmers will have updated in the near future, then I'm ready to go from 1.6 to 1.8.