* nd/clone-detached:
clone: fix up delay cloning conditions
push: do not let configured foreign-vcs permanently clobbered
clone: print advice on checking out detached HEAD
clone: allow --branch to take a tag
clone: refuse to clone if --branch points to bogus ref
clone: --branch=<branch> always means refs/heads/<branch>
clone: delay cloning until after remote HEAD checking
clone: factor out remote ref writing
clone: factor out HEAD update code
clone: factor out checkout code
clone: write detached HEAD in bare repositories
t5601: add missing && cascade