init PRACE Common Production Environment (CPE)

Summary: PRACE modulefiles have been working for a few months, on .lu side, w. mild usage.

PR does not implement the variables visible at http://www.prace-ri.eu/PRACE-Common-Production;
these should be provided via an alternative mechanism, possibly via Lmod sorcery.
Also, current code does not define `ftn` as spec'd in original PRACE/DEISA guidelines. TBD.

Ref: https://github.com/hpcugent/easybuild-easyblocks/issues/82#issuecomment-14033797 (largely covered)

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>