Exception if uninstalled extension has "wrong key"
I know of tons of installations where some deinstalled extension in typo3conf/ext/ gets renamed to "tt_news.old" or "news.bak" etc. This was no problem before.
With the new package management feature, this now throws an exception on first hit:
InvalidPackageKeyException('"' . $packageKey . '" is not a valid package key.', 1217959510)
The loop that scans for packages should skip those who's key is not invalid, in order to avoid an exception later down the road.