Some confirmations are useless when the game is finished
TileLayout: fix margins handling
Remove useless comments
Contribs: update Qt to version 4.8.2, and provide QtNetwork
MainWindow: do not show the visual rack until a game is started
MainWindow: try to reduce screen flicker when (re)starting a game
RackWidget: set small margins and draw a border
Arbitration: clear the filters when the rack changes, not when a search is performed
po: update the list of files to translate
po: re-generate po files
Fix make distcheck
Stats report: add "tooltips" to show the played move.

Implementation heavily based on a proof of concept by Joan Montané.
Fix c7913ddc454dd978c44ccf261eb84a3396e0ed9c.

This was not supposed to be commited.
MainWindow: no frame is needed for labels in the status bar