Add support for downloading and using meson subprojects, and build pkg-config with meson
This should speed up bootstrap and builds on Windows considerably.
ci: Don't use CERBERO_HOME in artifacts sections
Variable expansion does not take place in the same way in `artifacts:`
and in `script:` — see:
https://docs.gitlab.com/ee/ci/variables/where_variables_can_be_used.html#gitlab-ciyml-file
Fixes artifact upload failure on Windows.
build: use 'meson install' for meson recipes
.. and pass --skip-subprojects to it which is what we need
for pkg-config where glib is pulled in as a static subproject
but we don't want to install anything glib-related. Could just
patch it out of course, but this seems better.
cerbero: Recipes can now download meson subprojects
The purpose is entirely for subprojects that are used only at build
time, either as 'copylibs' that are built as part of the project or
built and statically linked into the project.
pkg-config will be using this to download and build glib. It cannot
pick that up from the cerbero prefix because... that requires
pkg-config.
pkg-config.recipe: build with Meson
Should reduce build times on Windows *a lot*.
Links glib statically into the pkg-config binary.
Downloads glib as subproject.
pkg-config.recipe: Use proxy-libintl tarball instead