Fix handling of paths when run outside the repo.
The main problem was that dirstate.getcwd() returned just "",
which was interpreted as "we're at the repo root". It now returns
an absolute path.
The util.pathto function was also changed to deal with the "cwd is
an absolute path" case.
#!/bin/sh
echo % init
hg init
echo % commit
echo 'a' > a
hg ci -A -m test -u nobody -d '1 0'
echo % annotate -c
hg annotate -c a
echo % annotate -d
hg annotate -d a
echo % annotate -n
hg annotate -n a
echo % annotate -u
hg annotate -u a
echo % annotate -cdnu
hg annotate -cdnu a
cat <<EOF >>a
a
a
EOF
hg ci -ma1 -d '1 0'
hg cp a b
hg ci -mb -d '1 0'
cat <<EOF >> b
b
b
b
EOF
hg ci -mb2 -d '2 0'
echo % annotate b
hg annotate b
echo % annotate -nf b
hg annotate -nf b
hg up -C 2
cat <<EOF >> b
b
c
b
EOF
hg ci -mb2.1 -d '2 0'
hg merge
hg ci -mmergeb -d '3 0'
echo % annotate after merge
hg annotate -nf b
hg up -C 1
hg cp a b
cat <<EOF > b
a
z
a
EOF
hg ci -mc -d '3 0'
hg merge
cat <<EOF >> b
b
c
b
EOF
echo d >> b
hg ci -mmerge2 -d '4 0'
echo % annotate after rename merge
hg annotate -nf b
echo % linkrev vs rev
hg annotate -r tip a