drop support for elgg_version in manifests

[cash]

It's useless when you have releases from more than one branch. No, actually it is dangerous because it allows you to enabled a 1.8 plugin on 1.7 if the version has been updated.

[brettp]

You can combine elgg_release and elgg_version to force 1.8 after a specific API version.

As long as the core devs stick to not changing the API or introducing anything during bugfix releases we can drop the elgg_version. We've already broken this on the 1.8 release for high profile bugs / features that wouldn't have been possible to do without adding functions or hooks.

[cash]

But why wouldn't I just set the release to 1.8.3 for example? I only see elgg_version as good for targeting something that wasn't released (like back in the day when Marcus would release a plugin on the community site and say it only works on a particular version in svn).

[brettp]

That's a fair point. Back then there was also more time between releases so people were mike likely to use SVN versions. Unless someone else has an argument for keeping it, I'm fine with deprecating it.

[ewinslow]

I'm also in favor of deprecating it for the reasons already discussed.