[Freeciv-Dev] (PR#12861) evaluate_improvements simplification

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12861 >

As the attached savegame shows, autosettlers pretty much break under
this patch.

1.  Mountains aren't mined or transformed.
2.  Deserts often aren't transformed.
3.  Farmland often isn't built.
4.  Roads aren't built on mined hills.

-jason