changelog redesign update

- Improves handling of deleted revisions.
- Import plugin disables after import.
- Check act reports if plugin is still enabled after the import.
- Import correctly handles summaries without the minor prefix.
- Newlines and tabs are now striped out of type, sum,
  and extra in the changelog.

darcs-hash:20060911014738-05dcb-2f6c9fdffb6346f7d3190610a72b290090b28097.gz