* regression from 1.0.3 (dont know precisely when)
When tech is not high enough, trying to build a grayed item, just close the item tray,
and show a message in the console only.
1.0.3 behavior is to let the item tray open, so info_bubble pop-up and shows the required tech.
* waterwell icon, tile (hmmm, must be redrawn by someone competent :-)
* info with query tool seems to not work on desert and trees, or work randomly
* bug of trunk = (re)initialisation of engine and UI is not enough. (max tech level...)