lp:~daggerstab/stellarium/satellites-080

Next version of the Satellites plug-in.

Work done so far (last revision is 5949, 2013-04-25):
- some changes, sometimes quite radical, to the class interfaces and how they interact; things have been shifted between header files
- any container with Satellite or SatelliteP objects can be sorted, including the main satellite list
- GUI: the satellites list now uses a model and a filtering proxy model instead of re-building the list to filter it
- GUI: cleanup of populating settings and lists
- GUI: moving and modifying some controls in anticipation of some changes
-- the satellites list now can show satellite hint colors
- improved update management:
-- "last update" now is marked on a successful update, not on initiating one
-- automatic adding of new satellites on update from the selected update sources; by default, only new naked-eye satellites are auto-added
-- GUI for selecting update sources for auto-adding
-- automatic removal of satellites if they are no longer listed in the update sources
-- "user-defined" flag protecting satellites from update/removal
- changes to the way update sources are saved to the configuration file (backwards-compatible - old settings are imported)
- translatable group names (for the default groups) and satellite descriptions
- GUI: mass operations over selections of satellites (right-hand box applies to all of the selection, not the current sat)
-- display and orbit display toggles with "partially checked" indicator
-- custom control for adding/selecting groups

Things I intended to do, but couldn't finish:
- optional visibility for manually added sats (now they are all visible by default)
- extracting orbit epoch from TLE and adding an option to hide satellites outside a range around the epoch
- GUI: color-picker control
- picking default and individual hint color (and orbit color? was that a separate thing?)
- option which info fields to display (or at least, just for the "extra" fields)
- re-organize configuration file options? (group flags with a "flag_" prefix?)
- reuse downloaded update files for manual selection of "new" sats?

- cleanup of testing code and TODO comments before proposing a merge!

Perhaps for a later version:
- GUI: TLE set editing?
-- TLE set regexps and validators (can be used in multiple places, make the strings static members of the appropriate class)
- GUI: comm link editing?

It will be proposed for merging before the next major release (i.e. after 0.12.1, as it's supposed to be a bugfix release).