Cleared out minor bugs with Ready states.

Previously, user was able to alter the layout on Arrangement
screen even after he pressed Ready button. There was also
no way to uncheck this button. Now these are fixed.

The problem with not being able to uncheck Ready button also
appeared on Results screen. It is fixed as well now.
Added invalid imaginary ship positon highlighting.

Now when placing ship on Arrangement Screen the ship image which
flyes around with mouse will change its green color to red if
click in current position will result in an invalid placement.

There is some wandering bug though, involving the size of the ship.