* New upstream release from the beta channel (FIREFOX_73_0b3_BUILD1)
* Drop browser/chrome.manifest which is not available or required anymore
  - debian/firefox.install.in
* Bump build-dep on rustc >= 1.39.0 and cargo >= 0.40
  - debian/control{,.in}
* Update patches
  - debian/patches/support-coinstallable-trunk-build.patch
  - debian/patches/ubuntu-ua-string-changes.patch
* Fix build with C++17 on ppc platforms
  - debian/patches/ppc-drop-register.patch