GitLab

the 'modules' commands won't show us what we are looking for now that
spack does all that itself.

- includes two bake builds: one with pmdk, one with file backend
- actual runs do not work yet due to a mount problem

- set $HOME to avoid perturbing ~/ config files for the user running this script
- remove deprecated --dirty and LD_PRELOAD hacks
- remove explicit set of SPACK_ROOT in favor of variable set by spack itself
- other misc streamlining improvements

- build and run against mvapich with verbs support
- use newer gcc
- don't do dirty builds

- also update yaml to build fewer spack packages

- also rename some scripts and email headings for consistency