Wiki change (oops)

I wanted to add a point to the 83ReleaseFeatures page on the wiki. Did
that, and upon saving it seems it ate about half the page - parts that I
certainly didn't edit.

Anyway. I can find the revision history, but I can't figure out how to
revert the changes and go back to the earlier version. Can someone who
knows how to handle the software please do that? (And feel free to tell me
how to do it)

And when at it, please add something along the line of what I added earlier
- if I do the same thing again, it'll likely eat the page again.

//Magnus