git-svn expects its references under refs/remotes/*; but these will
not be copied or set by "git clone"; put in this man page the manual
fiddling that is required with current git-svn to get this to work.
Signed-off-by: Sam Vilain <sam.vilain@catalyst.net.nz> Signed-off-by: Junio C Hamano <gitster@pobox.com>