Revert "cleaned up archive_tree function"

This reverts commit 1d03df5c8588e297a287de07cb89dbf666308773.
Revert "fixed tar bug :)"

This reverts commit 88e18ff8ccd7fd9a69be2c649eaff85adb3bacdf.
fix empty leading slash entry, for real

this also preserves empty directories in tar files
prepare for 0.0.6
Merge pull request #12 from dzuelke/tarball

Fix tarball creation, for real :)