Added HPL README to copying_headers/MANIFEST.EXEMPT.
Added HPL README to copying_headers/MANIFEST.EXEMPT.

geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm