Long setup time due to hwloc. Add store/load cpuset configuration

[bartgol]

hpcbind can take several seconds to inspect the architecture and get the final cpuset desired. For a script that launches several simulations with the same cpuset configuration, this can cause a significant overhead (especially if simulations themselves are "fast").

I would suggest adding the capability to store the HPCBIND_* variables to file, and load them on a subsequent run. The idea is that loading the env variables from file should be faster than continuously calling hwloc-ls.

[dsunder]

Reduced setup time, but still need to add an option to load from file.