buildsys: release 0.9.3
buildsys: release 0.9.3

It also adds new file with release notes.

Conan-Kudo/libhif,rpm-software-management/libdnf,edynox/libdnf,hughsie/libhif,edynox/libdnf,rpm-software-management/libdnf,rpm-software-management/libhif,Conan-Kudo/libhif,rpm-software-management/libhif,hughsie/libhif,edynox/libdnf,edynox/libdnf,rpm-software-management/libhif,rpm-software-management/libdnf,hughsie/libhif,Conan-Kudo/libhif,rpm-software-management/libhif,Conan-Kudo/libhif,rpm-software-management/libdnf,hughsie/libhif