when choosing the delivery mode, check for the existance of libthread *and* the patch for aolserver to make bgdelivery work (naviserver has thison default),
1. Bumped version to 5.2.3b12. Removed dependency made by Malte on acs-translations, a package that has not been added to acs-core, and which is currently empty on HEAD as well as the 5.2 branch. When it does something, restore the dependency and add the package to acs-core.
added third delivery mode "scripted-streaming", which works on safari and IE as well. This is used on default, when libthtread is available. without libthread, it uses polling.