test-subrepo-paths: use printf instead of echo
Different shells have different opinions on how to backslashes must be
escaped for echo, but printf is consistent across zsh, dash, bash,
tcsh, and csh.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.