Spaces are not stripped from script names when generated.

The way the current script generation looks is as follows:

to_be_scheduled, script_path, restart_path = \
            self._write_script(ws_path, step)
        st = os.stat(script_path)
        os.chmod(script_path, st.st_mode | stat.S_IXUSR)

        if restart_path:
            st = os.stat(restart_path)
            os.chmod(restart_path, st.st_mode | stat.S_IXUSR)

        return to_be_scheduled, script_path, restart_path

The _write_script method is the abstract backend method that handles writing the scripts and is overwritten per derived class. The write_script method is the interface method that presents a consistent interface to other code, but the structure above makes it difficult to handle making script names path safe (the primary thing here is that script names can have spaces). While this doesn't seem to hinder anything currently, it can become problematic just like the lack of consistent calling that was fixed in PR #157.

Start with the write_script interface and its abstract _write_script method, then inspect the derived backend implementations that generate scripts. Compare the calling structure with the consistency change in PR #157. Done means generated script names are path-safe when they contain spaces across the affected backends.