debian: build and package our own Qt

Makefile

docker/Dockerfile_debian_10_qt

docker/Dockerfile_ubuntu_18.04_qt

docker/Dockerfile_ubuntu_18.04_qt_i386

docker/Dockerfile_ubuntu_20.04_qt

docker/Dockerfile_ubuntu_20.10_qt

packaging/rules/debian-qt/compat

packaging/rules/debian-qt/control

packaging/rules/debian-qt/libqt-jami-env.sh

packaging/rules/debian-qt/libqt-jami.install

packaging/rules/debian-qt/rules

packaging/rules/debian-qt/source/format

scripts/build-package-debian-qt.sh

scripts/deploy-packages.sh

scripts/make-packaging-target.py