* New upstream stable release (69.0build2)

[ Olivier Tilloy ]
* Re-enable and update debian/patches/unity-menubar.patch
* Stop building and remove firefox-globalmenu (LP: #1834866)

[ Rico Tzschichholz ]
* Update cbindgen to 0.9.0
  - debian/build/create-tarball.p
* Use firefox-*.json to retrieve revision
  - debian/build/create-tarball.py
* Bump build-dep to clang-8 and llvm-8-dev
  - debian/config/mozconfig.in
  - debian/control{,.in}
* Bump build-dep on rustc >= 1.35.0 and cargo >= 0.36
  - debian/control{,.in}
* Update patches
  - debian/patches/ubuntu-ua-string-changes.patch
  - debian/patches/unity-menubar.patch
* Drop upstreamed patches
  - debian/patches/skcms-workaround-gcc-bug.patch