- replace `spack.config.get_configuration()` with `spack.config.config()`
- replace `get_config`/`update_config` with `get`, `set`
- add a path syntax that can be used to refer to specific config options
without firt getting the entire configuration dict
- update usages of `get_config` and `update_config` to use `get` and `set`
* Edits to get setup-env.csh working better.
Autosets the sys_type a la setup-env.sh
* More stealing from bash setup script for module roots
* Add error message if SPACK_ROOT isn't set
* Remove _sp_lmod_root per Adam J Stewart
