Update of bundled libraries

[Piraty]

Hi,

in order to address void-linux/void-packages#18293, i ran into quite a few build errors.

Most i can address myself, but i refuse to backport all gcc8-compat patches librawspeed has up to now.
Please consider updating the bundled sources such as and cut a new release.

What i found out:

• bundled librawspeed fails to build with gcc>=8
• exiv2-0.27.2 has header <exiv2/xmp_exiv2.hpp> instead of <exiv2/xmp.hpp>
• libvips-8.9.0 requires <vips/vips7compat.h> (for some IM_...)