[RFC] TKO Improvements

The main goal of this work was to drop the legacy database layer located under `autotest.tko`.

The users of that database layer are:

   * `autotest-db-delete-job`
   * `autotest-tko-parser`
   * various CGI scripts

The current state of this pull request allows the first two items listed (far more important than the CGI scripts IMHO) to run without the legacy DB layer.

But, to completely remove them of the tree, we need to port the various CGI scripts also. Some work has been done in that area, but there are many still left to do.

This brings me to the point where I'd like to have some comments: are there real users out there of the CGI scripts? Which ones?

In all honesty, I feel inclined to drop them, since the functionality should be in the `new_tko` module.

If you care about the CGI scripts, please say so, because if people tell me they should go, I'll gladly accept their suggestion!

BTW: the patches are very granular and incremental. It was the way to keep my own sanity during the development process and I believe it'd help patch review.