Nominating a bug for a series not a release

Launchpad series and releases overlap somewhat. However, it's useful to think of them this way:

 * Series: planning towards a future release.
 * Release: marks the fact of a release that has happened.

Perhaps a better name for series would be "planned release".

The bug is this: when nominating a bug for a future series, the Actions menu item and other text talks about nominating or targeting it to a release. Although this makes sense, in that outside Launchpad people typically refer to releases in this way, in Launchpad terms it is confusing.

A release in Launchpad marks an event, allows you to publish a changelog and make files available for download. You cannot target anything to a release, as it is something that has already happened.

So, this should be "Nominate/target to a series". Although that makes less immediate sense to the user, it might save some confusion over what a series is and what a release is. However, we should also deal with bug 174468 (Series, releases, and milestones overlap confusingly) by at the very least selecting a more obvious name for series. I see why series are so named and I think it makes sense after explanation but we shouldn't have to explain it.