Add a pointer to "hg -v help" to the bottom of hg help {,cmd} output
This should make it easier to discover global options.
As a bonus, they are no longer displayed by something like a
hg -v help dates
#!/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