Using the "svn_cmd" wrapper instead of "svn" alone allows tests
to run consistently for users with customized
~/.subversion/configs. Additionally, using subshells via
"(cd ...)" allow cleaner and less error-prone tests to
be written.
[ew: expanded commit message]
Signed-off-by: Marc Branchaud <marcnarc@xiplink.com> Acked-by: Eric Wong <normalperson@yhbt.net>