* Refactor platform etc. to avoid circular dependencies
All the base classes in spack.architecture have been
moved to the corresponding specialized subpackages,
e.g. Platform is now defined within spack.platforms.
This resolves a circular dependency where spack.architecture
was both:
- Defining the base classes for spack.platforms, etc.
- Collecting derived classes from spack.platforms, etc.
Now it dopes only the latter.
* Move a few platform related functions to "spack.platforms"
* Removed spack.architecture.sys_type()
* Fixup for docs
* Rename Python modules according to review
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