Log Message:
* update to 0.7.0; changes include:
  - 'showwants' now prints a visually nicer and sorted list. 
  - Add -f flag to sync to supress confirmation dialog. 
  - Consider both /etc/mk.conf and $PREFIX/etc/mk.conf when detecting
    mk.conf changes. 
  - Summary cache: Use recursively latest modification time
    instead of pkgsrc directory modification time when deciding whether
    a summary needs to be updated. This should eliminate some (or hopefully
    all) of the reported cases where pkgmanager must be explicitly told
    to flush the summary cache in order to pick up a dependency change
    (assuming strictly increasing system time).