* Merge upstream bugfix release from Debian unstable. Remaining changes: - Switch lttng-gen-tp script to use python3. - Add python3 build-dependency. - Add ppc64el and arm64 host_cpu stanzas in configure.ac - Enable builds on arm64 and ppc64el. * Don't bump liburcu build-depend/depend as the new version isn't required and won't be in 14.04.