data-package-build: backport from CMSSW_7_0_X

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
Merge pull request #232 from davidlt/backport-data-package-build-from-70X

[CMSSW_6_2_X] Backport data-package-build.file from CMSSW_7_0_X