tests/test-issue1089

Fix how setup.py identifies the Mercurial version.

There is a problem with setup.py where it will not identify the Mercurial
version properly when not being ran in within a repository even if
mercurial/__version__.py exists.

To fix, use mercurial.__version__.version when available before defaulting
to "unknown".  (Using mercurial.util.version() is not an option due to a
dependency issue where osutil can be referenced before it is built.)

#!/bin/sh

hg init a
cd a
mkdir a
echo a > a/b
hg ci -Am m
hg rm a
hg ci -m m a

mkdir a b
echo a > a/b
hg ci -Am m
hg rm a
cd b
# relative delete
hg ci -m m ../a