Automatically determine paths when root_universe is assigned.
Automatically determine paths when root_universe is assigned.

amandalund/openmc,wbinventor/openmc,mit-crpg/openmc,shikhar413/openmc,bhermanmit/openmc,mit-crpg/openmc,paulromano/openmc,amandalund/openmc,liangjg/openmc,liangjg/openmc,walshjon/openmc,johnnyliu27/openmc,johnnyliu27/openmc,paulromano/openmc,paulromano/openmc,wbinventor/openmc,shikhar413/openmc,smharper/openmc,walshjon/openmc,walshjon/openmc,amandalund/openmc,paulromano/openmc,walshjon/openmc,bhermanmit/openmc,liangjg/openmc,johnnyliu27/openmc,wbinventor/openmc,shikhar413/openmc,smharper/openmc,smharper/openmc,amandalund/openmc,wbinventor/openmc,johnnyliu27/openmc,mit-crpg/openmc,shikhar413/openmc,smharper/openmc,liangjg/openmc,mit-crpg/openmc