New workflow in the Observation Planner: Sort by % max. alt achieved

Adding a new workflow in the Observation Planner that helps find
objects for observation without having to prepare a session plan with
assigned times.

1. Add all objects that you want to observe to the Wish List

2. On the observing field, sort by the "Current Altitude" column in
   descending order. The column contains the percentage of the maximum
   altitude currently achieved by the object. The altitude uses the
   geographic location set in the observation planner, but _ignores_
   the date field -- so it is really current in system clock time.

3. The list is automatically updated and dynamically sorted every 2
   minutes, so you can always observe the objects at the top of the
   list. As objects rise and set, they move up/down the list.

Improvements needed:

1. Support multiple wishlists, save wishlist, load wishlist etc.

   [ Or alternatively, move the feature to the session plan, although
   the session plan file format is more complicated]

2. Make the workflow more obvious

   (Any pointers on how to do this will be very helpful)

3. Support demotion of objects after "checking them off"

4. Have an option to demote objects that are in the Dobsonian hole.

FEATURE:
GUI:
CCMAIL: kstars-devel@kde.org