fix(stage-copy): cwd expand file options not copying to stage directory

This should resolve issue #8.

Biggest change was to checking if the item.orign had a dest instead of just item as the grunt files option populates those for you. Then using that generated item.dest for output into stage dir instead of the item.src because it has the full relative path not the path from the cwd.

Broke out some of the logic in the build to stage dest conditions into functions to add some clarity.