Merge branch 'jn/scripts-updates'

* jn/scripts-updates:
  remove #!interpreter line from shell libraries
  test: replace shebangs with descriptions in shell libraries
  test: make FILEMODE a lazy prereq
  contrib: remove git-p4import
  mark contributed hooks executable
  mark perl test scripts executable
  mark Windows build scripts executable

diff --cc contrib/completion/git-completion.bash
Simple merge

diff --cc t/lib-read-tree.sh
Simple merge

diff --cc t/test-lib.sh
Simple merge