kde: Copy 4.12 to 4.14 as a base"
kde: Some tweaks to kde-manifest.sh
- Allow packages with different versions than $release (kde-workspace)
- Extra checks

This is a copy of https://github.com/wmertens/nixpkgs/commit/41faadbcce71226386ebc334bc02070492756f9a
but for 4.14.
kde-4.14: Fix source for module subdirectory packages.
Add non-legacy qt-gstreamer.
Only compile tested (needed by Artikulate in KDE 4.14).
kde-4.14: Initial porting.
Nix evaulation succeeds (but probably not building everything).
kde-4.14: Adjust fixed output hashes.
indilib: Add version 0.9.9.
kde-4.14: Make it all build.
kde: Allow kde_next as a desktop environment

This is the same as
https://github.com/wmertens/nixpkgs/commit/93fda9e353bb9408ea80339f36fa513742d65ddf