utilizes the cyclus::eps_rsrc() value to avoid exceptions being thrown because of floating point errors in material amounts.
Merge branch 'eps' of github.com:katyhuff/cyclus into eps-extract
added some clarity to extract source block
removed superfluous semicolon
Merge pull request #472 from katyhuff/eps

utilizes cyclus::eps_rsrc() to fix extraction of one comp from its duplicate.