Minor enhancements to Python config stuff:

Minor enhancements to Python config stuff:
- Add support for assigning NULL to SimObject pointers.  In Python,
this is a special value, distinct from None.
- Initial, incomplete pass at regenerating C++ parameter code (declarations
and INIT_PARAM macros) from .odesc files.

util/config/m5config.py:
    - Add support for assigning NULL to SimObject pointers.  In Python,
    this is a special value, distinct from None.
    - Initial, incomplete pass at regenerating C++ parameter code (declarations
    and INIT_PARAM macros) from .odesc files.

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extra : convert_revision : d7ae8f32e30b3c0829fd1a60589dd998e2e0d0d7