Merge branch 'se/http' into next

Merge branch 'se/http' into next

* se/http:
  Remove possible segfault in http-fetch.
  Install git builtins into gitexecdir rather than bindir.
  Change GIT-VERSION-GEN to call git commands with "git" not "git-".
  cvsimport: replace anonymous sub ref with a normal sub
  cvsimport: minor fixups
  Problem: 'trap...exit' causes error message when /bin/sh is ash.
  Avoid segfault in diff --stat rename output.
  Tutorial #2: broken link fix.
  git help: remove whatchanged from list of common commands