Territory influence tooltips

[elexis]

Persian halls, palaces, wonders, monuments, the ishtar gate and a some more buildings have root territory influence.

There should be a generic tooltip showing this information (addition to tooltips.js). It should be shown in the tech tree (add entry to draw.js) and in selection_details.js.

Not sure about showing the territory radius if the entity isn't a root.

The hardcoded tooltip of some buildings like the iberian monument will have to removed:

Buildings in the territory of the monument do not decay.