list files again to avoid owning standard dirs in RPM

reverts commit 9d256d93a59302c06d26f36c88125ce574d7e360

fixes file /usr/bin from install of openra-release.20130915-1.noarch
conflicts with file from package filesystem-3.2-13.fc19.x86_64
cope with with data file names that contain spaces
Use a combination of find xargs and read to prevent file/dir name problems.
Use quotes around rpm file names to prevent issues with spaces.
Merge pull request #3836 from Mailaender/rpm-filesystem

List files again to avoid owning standard dirs in RPM