New profile: small cleanup of heartrate code

Remove unused variable and correct comment.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
New profile: fix tooltip display for events

We need to use the transform() of the view, not the tooltip.

Suggested-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
New profile: try to pick better HR samples for which to print number

This simply tries to pick at least local minima / maxima.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>