hgweb: use generator to count parity of horizontal stripes for easier reading. - use web.stripes in all places and consistently - start with parity0 for lists generated in reverse (e.g. changelog)

#!/bin/sh

hg init a
echo a > a/a
hg --cwd a ci -A -m a
hg clone a b
echo b > b/b
hg --cwd b ci -A -m b
chmod 100 a/.hg/store
hg --cwd b push ../a
chmod 700 a/.hg/store