Minor changes to support Percona Toolkit's heartbeat implementation, since PT has superseded maatkit, along with a few small documentation fixes.
Thank you for your contribution!
This looks good to me.
I'd just have one request which would be to squash the last commit with the first one if that's possible. And then I'll merge the PR.
Switch heartbeat support from maatkit to Percona Toolkit.
Reflect maatkit -> Percona Toolkit change in documentation.
Correct --password option typo.
Clarify that --slave is required for --heartbeat to work.
I squashed the two commits that were fixes of my own mistakes, so I think this is ready to merge. Thanks!