Added FPS display
Added methods to add and remove blocks from a grid
Replaced some instances of add/remove grid blocks
Moved grid tests to appropriate namespace
Added remove-and-add-blocks
Added test for disappearing blocks
Refactored disappear blocks
Simplified falling blocks creation
Refactored resolve swap empty
Refactored resolve falling
Removed dupe defn of remove-blocks
Made all callers of remove-block pass in a set
Added hash/unhash funcs for grid
Changed grid to be created using add-row
Removed unused binding expr
Fixed problem with test
Updated tests to fit new grid interface
Changed fps text location