tests & help: fix compatibility with Mercurial 1.4 and earlier. The --branch option to clone, pull, etc., was introduced in 1.5, and our handling of it assumes that Mercurial also provides it. As a result, both documentation and the test are changed to reflect this.

#!/bin/sh
. $(dirname $0)/common.sh

for b in `hg branches -aq` ; do
    hg co $b || break
    echo verifying $b
    hg svn verify
done