Revert "Merge #3054: add kde 4.13.2"

This is due to breaking evaluation; see the PR discussion.

This reverts commit 6a77d5fd3e3eef8c9eafb53f70a9448c25d2f517, reversing
changes made to 07a09fbe63192de7b62468d38f7ed8b7981062a4.

Conflicts:
	nixos/modules/services/x11/desktop-managers/default.nix
blender: use permanent URL for the patch

No hash changes.