Bug fix : Package.ps1 have bug possibility of removing Empty Directory even it's child have file.

Description
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When targets was copied, empty Directory (not contains any file) will be deleted.

Issue Detail
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If there are
c:\hoge
c:\hoge\fuga\piyo.exe
Old script will remove c:\hoge as there are no files right under c:\hoge.

Fix
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Now I added file tree check to prevent these issue.
Please check detail how it works at http://tech.guitarrapc.com/entry/2014/08/12/081637