Renamed viewModel to gameController and controlPanel to optionsView
Fixes #3: middle click discloses cells surrounding the clicked one
Refactored the controller: removed all logic from event handlers
Bind click on mouse up rather than mouse down
Highlight a cell when left click
Minor restyling in the controller code
Highlight surrounding cells on middle click
Chaining event handlers
When middle clicking on a cell with wrong number of blocked cells, highlights the number of bombs in red
Highligh cells on middle click only when hidden