o Enable thread support using pth-syscall and nathanw_sa. The
later has problems which are being worked on.
o Restructure the build of certain plugins so that qt3-libs
comes with jpeg and mng support.
o Introduce a BUILDLINK_DEPENDS_METHOD.qt3-tools variable that
when set to build means we don't get a full dependency on
qt3-tools.
all dependencies on packages depending on "png" which contain shared
libraries, all for the (imminent) update to the "png" package.
[List courtesy of John Darrow, courtesy of "bulk-build".]