(packaging) Remove createpackage.sh from facter

This shell script has been replaced and superceded by the packaging rake tasks.
Running `rake package:bootstrap` followed by `rake package:apple` will build a
dmg locally in a similar manner to this script.
(packaging) Remove PackageInfo.plist, it is no longer used by packaging.
Merge pull request #490 from haus/remove_createpackage_sh

(packaging) Remove createpackage.sh from facter