Merge pull request #4773 from RosettaCommons/vmullig/skip_submodule_update_with_nover_option
Two small tweaks to scons build system
This pull request:
- Alters the behaviour of the --nover flag, so that in addition to skipping the versioning script, it skips the submodule update script. This saves time on slower filesystems during rapid rounds of development and compilation, if the developer knows that these submodules do not need to be updated.
- Updates the help that one sees with `./scons.py --help` to:
- Add examples for mpi, serialization, and cxx11thread builds.
- Add the recommended default compilation command to build vanilla Rosetta for production runs.
- Clarifies that `-j` accelerates _builds_ and not _Rosetta execution_, while `extras=mpi` or `extras=cxx11thread` can accelerate _Rosetta execution_ and not _builds_.
- Adds the `--nover` flag to the help.