Merge pull request #44 from tampakrap/eselect_fact

updates/bugfixes in eselect facts
Merge pull request #42 from tampakrap/empty_entries

Add ability to specify empty (unversioned/unkeyworded) entries in
(maint) fix use of regex cluster
Revert "(portage-#41) Default package_* to present"

This reverts commit 31b53b9738448c2d7844b0c0523b0315e3eb0b4e.

Git bisect indicates that this caused #45.