The changes in commit 47b060ae (CPackDeb: allow empty directories in
component packages, 2015-09-21), commit b58de9fe (CPack: allow packaging
of empty directories, 2015-09-21), and commit b761e90d (CPack: remove
accidental changes, 2015-09-22) regressed packaging of CMake itself.
Revert the changes until they can be revised and rebased on other
changes that make additional fixes.