(#17434) Revert "Merge pull request #29 from timurbatyrshin/puppet-style"

This reverts commit b48694063d890b821928cf578defff1d70084845, reversing
changes made to 422c386f36980d5e080666ec0d12137ad0bc7ba9.

This change caused top scoped lookups (eg "%{::var}") to be retrieved from a
local scope.

Conflicts:
	lib/hiera/backend.rb