Revert "Merge branch 'graphene' into 'master'"

.gitlab-ci.yml

CONTRIBUTING.md

LICENSE

README.md

build-aux/cross/fedora-mingw32.txt

build-aux/cross/fedora-mingw64.txt

build-aux/make_release.sh

build-aux/uncrustify.cfg

configure

doc/.gitignore

doc/CODING_STYLE.md

doc/graphene-docs.xml

doc/graphene-overrides.txt

doc/graphene-sections.txt

doc/meson.build

doc/rectangle-intersection.png

doc/rectangle-intersection.svg

doc/rectangle-union.png

doc/rectangle-union.svg

doc/rectangle.png