Working changes w/ debugging enabled

This series of changes is a good beta candidate.  Some debug statements
are still enabled, mainly because I'm trying to track down some bugs in
the original version.  Things I've changed thusfar:

- Removed CityView UI elements; conflicts with CivUP;
- Fixed the tooltip text (English only) to read properly; added
prosperity information to tooltip;
- Disallow migration-from on the same turn population grew;
- Populations are now saved in save game (for the above point).