added more comments, only copy logfile if found, remove gfortran warning
added more comments, only copy logfile if found, remove gfortran warning

nhorelik/openmc,liangjg/openmc,smharper/openmc,amandalund/openmc,lilulu/openmc,sxds/opemmc,mit-crpg/openmc,bhermanmit/openmc,paulromano/openmc,wbinventor/openmc,johnnyliu27/openmc,liangjg/openmc,mit-crpg/openmc,amandalund/openmc,walshjon/openmc,kellyrowland/openmc,bhermanmit/openmc,shikhar413/openmc,sxds/opemmc,paulromano/openmc,paulromano/openmc,shikhar413/openmc,lilulu/openmc,mit-crpg/openmc,nhorelik/openmc,wbinventor/openmc,walshjon/openmc,samuelshaner/openmc,smharper/openmc,mjlong/openmc,samuelshaner/openmc,johnnyliu27/openmc,johnnyliu27/openmc,shikhar413/openmc,walshjon/openmc,liangjg/openmc,amandalund/openmc,lilulu/openmc,walshjon/openmc,samuelshaner/openmc,paulromano/openmc,mit-crpg/openmc,liangjg/openmc,shenqicang/openmc,wbinventor/openmc,samuelshaner/openmc,amandalund/openmc,smharper/openmc,shikhar413/openmc,mjlong/openmc,wbinventor/openmc,johnnyliu27/openmc,kellyrowland/openmc,shenqicang/openmc,smharper/openmc