[eclass] Remove unused function.

Some packages released with Plasma 2 were originally part of extragear (which
means they belong in kde-misc). Since those packages are now moved to
kde-workspace, they can to go kde-base and we no longer need an extra special
function to handle the versioning.
[eclass] Punt bogus deps.
[eclass] Catch more cases of bogus deps.
[x11-libs/libkscreen2] Move back to x11-libs/libkscreen due to another upstream change.

Now only the tarball is renamed.
[kde-base/plasma-workspace] Use correct libkscreen package name.

Package-Manager: portage-2.2.10
[kde-misc/kscreen] Use correct libkscreen package name.

Package-Manager: portage-2.2.10
[sets] Update for libkscreen rename.
[profiles/package.mask] Update for libkscreen rename.