bp - don't use --git-force-create to not rebuild the .orig.tar.gz which should already exists from the downloaded files upon git-import-dsc.
bp - no need for --git-debian-branch when --git-ignore-new is used.
bp - add an option to set a target distribution upon build with dch; backport by default; sync help and man.
bp - nmudiff expects the .dsc file to be ../ from the build tree