Accessibility: Make descriptions global

[sukiletxe]

So far in the game, I have encountered accessible descriptions in the purchase screen of the first stage of the game, and in the civilizations screen (buildings part). However, from experimentation, I have seen that tooltips appear in lots of more places. From what I understand, it seems that tooltips appear when hovering over certain items, and that if focus moves away (I don't know if the mouse moves too) the text disappears. So tooltips could be made to follow the "description link" pattern (as in the examples above), or a static text could be added when clicking (or pressing enter) over items which have tooltips along with a "close" button, like trimps does.