Now, only the empty squares contain a GestureDetector.
The GestureDetector is not necessary anymore in squares with pieces
because the tap is started when the drag is started.
This adds an option to dragging-and-dropping which is slightly hard on
smaller screens.
Fix promotions when tapping and fix handling of subsequently tapping two pieces of your color
Cancel tap if a drag is started (tapped square will not stay red in case a drag is started)
Change url strategy back to the hashtag thing
Change version
Fix bug that would not allow a piece move if you tried to take an opponents piece.
Fix the coloring of the last move after an invalid move was played.
Upgrading deps
This is another step to allow reconnecting after connection loss or
browser closing.
When the game is left with the X button on the bottom right, we will
close the websocket connection, to let the server know, that we are
gone.
The server still has issues that prevent this from working flawlessly.
Remove unused import
1. Fix the bug that made black move first in a new game when the old
game was ended during blacks turn.
2. Fix bug that offered the promotion dialog to the player when a pawn
was moved on the last rank from any square
Also, a late initializer error was fixed because the wrong move variable
was used when a pawn reached the last rank.
