Make spaces per indent configurable for clean_xml_indentation
Make spaces per indent configurable for clean_xml_indentation

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