Major cleanup of installation. Removed hard-coded directory paths.
CMake does not try to compile wrappers automatically any more as this adds plenty of dependencies.
Option added to allow building of wrappers (as has been done in the past).
Fixing of wscripts to deal with changed siox-inst behavior.

Waf: Allow parallel installation of multiple wrappers (MPICH2 vs. OpenMPI).
Added devel/scripts/build-wrapper.sh script to simplify installation of wrappers.