Improved browsing in search

[erlend_sh]

Once I've searched something, I'd like to be able to sort the outcome as I wish according to "Relevance", "   Started by" and "Date Posted". So if the post I'm looking for is very old, I would just clikc the "Date Posted" heading and it should first sort the topics from newest to oldest, then from oldest to newest if I clicked again. Same thing with the others.