xspec v11 bug in HEAsoft 6.3

One of my minor mods to xspec v11 to support the use of the gfortran compiler introduced a bug in the addcomp command - inserting a component into the model caused the name of the final component to be changed to CPCMOD. Thanks to a report from Lisa Winter we caught this within a week of the HEAsoft 6.3 release and have updated the tar files.