Merge branch 'ph/transport-with-gitfile'

* ph/transport-with-gitfile:
  Fix is_gitfile() for files too small or larger than PATH_MAX to be a gitfile
  Add test showing git-fetch groks gitfiles
  Teach transport about the gitfile mechanism
  Learn to handle gitfiles in enter_repo
  enter_repo: do not modify input

diff --cc cache.h
Simple merge

diff --cc daemon.c
Simple merge

diff --cc transport.c
Simple merge