Divorce opened/closed status and classification.
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We need to track open/closed status and classification independantly.

Classification is one category, status should be another. Possible values for
status:

* new
* resolved
* awaiting validation
* rejected
* reassigned

For the file-based issue implementation, the file format changes from
``nnnnsp`` to ``nnnncsp`` where:

    * ``nnnn`` still represents the bug number (no change)
    * ``c`` represents the *category* (used to be ``s`` the status):

        * ``b``: Bug
        * ``f``: Feature
        * ``t``: Task

    * ``s`` represents *status*, a new field:

        * ``a``: Reassigned
        * ``j``: Rejected
        * ``n``: New
        * ``s``: Resolved
        * ``v``: Awaiting Validation
    * ``p`` still represents priority, ``0`` being the highest and ``9`` the
      lowest.