tests/test-diff-color

rebase: improve error and debug messages

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "color=" >> $HGRCPATH

hg init repo
cd repo
cat > a <<EOF
c
c
a
a
b
a
a
c
c
EOF
hg ci -Am adda
cat > a <<EOF
c
c
a
a
dd
a
a
c
c
EOF

echo '% default context'
hg diff --nodates --color=always

echo '% --unified=2'
hg diff --nodates -U 2  --color=always