* don't double free an object! Thanks to nivix for pointing me to the right direction and keeping to bug me about this. Fixes #978

* publish gvp support to launch-services (this was enabled in /trunk a long time ago, but forgotten to be back-ported to 0.8.6)

* download the SDL stuff from sourceforge instead of the bogus official server, as the SF park is much faster and more reliable

    - this allows native compilation on future darwin and current win32 releases
    - more recent library version (0.3.9 instead of 0.3.8)
    - [18618], [18552], [18530], [18525], [18524] (partially)

I am very suspicious about the original commit to trunk by the way
(Why is signed int wrong in one place and right in the others?
 Could be, but really looks unlikely to me)

Please retain the branch alive at least until 0.9.0 is out (if ever);
you can still tag release individually

Hopefully, we won't run short of letters
(but we still have 0.8.7a-0.8.9z too, which means 100+ possible releases)