Release of version 2.2.

This is a full release which features a new header cache updating and filtering architecture. Also includes numerous bug fixes, and a great deal of general maintenance.

Upgrading from any previous version to v2.5 is easy - just replace the ubh executable. Your existing .ubhrc and .newsrc files are entirely forward compatible with v2.2.

    Miscellaneous Maintenance:
        * Greatly improved performance and reduced memory usage.
        * Now properly handles multiple [xx/yy]'s in Subject.
        * Eliminated -r and -Z options.
        * Now uses MIME::Parser parse_DFS() to iterate
          over MIME articles.

    Bugs Fixed:
       513063 -r bug (OBE)
       513075 Add '<' and '>' to mandatory filter
       513080 Articles downloaded in random order
       513085 Improve -u description
       513091 MIME embedded filename badness

    Feature Requests Implemented:
       513062 Apply -I/-X and newsrc earlier
       513073 Add 'p' to default single and multi exts
       516455 yEnc support