Merge branch 'jc/test-lib-source-build-options-early'

Reorders t/test-lib.sh so that we dot-source GIT-BUILD-OPTIONS that
records the shell and Perl the user told us to use with Git a lot
early, so that test-lib.sh script itself can use "$PERL_PATH" in
one of its early operations.

* jc/test-lib-source-build-options-early:
  test-lib: reorder and include GIT-BUILD-OPTIONS a lot earlier

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