Meson and Ninja Approved

This morning, Patrick has pushed three new packages for Slackware-Current, in which one of them is also part of my wishlist, meson build. This will allow future mesa and xorg to be build since they have moved on to meson build and soon they will abandon autoconf-based build. I believe many others will follow their move as meson proved to be faster than other builder. Ninja also goes in as well since it's a dependency for meson.

Another big think is the inclusion of qpdf 7.0.0, binutils 2.29.1, and poppler 0.59.0. This brings some changes in the shared library, so other packages that linked into this library will have to be rebuilt (including atril in my MSB).