Grouped timer-related code into Game.timer object.

init_clock() -> init_timer()
reset_clock() -> timer.start()
set_time(0) -> timer.reset()
max_time -> timer.set_max_time()
clearInterval() -> timer.stop()
time -> timer.get_time()
View.set_time() -> timer.display()
Grouped click-related code into Game.clicks object.

set_clicks(0) -> clicks.reset()
set_clicks(clicks+1) -> clicks.increment()
clicks -> clicks.value()
View.set_clicks() -> clicks.display()
init_clicks(), clicks.is_odd?()
Grouped more functions.

Grouped all internationalization code into init_i18n().
Grouped start-game end-game related code into Game.state object.
Grouped level related code into Game.level object.
Reordered function declarations.
Moved View functions into Game object.

More grouping and use of closures.
Moved on-click event from '.tile' to '#tiles'.

There are multiple '.tile' elements, but only one '#tiles' element.
  Instead of attaching the same event to multiple '.tile' elements,
  attach it only to the '#tiles' element for better performance
  and encapsulation.
Fixed 'click count' bug.

Reset click count when start-game button is clicked.
Refactor: rename, reorder, regroup

A lot of renaming, reordering, and regrouping.
Almost no change in behavior.
Performance improved by avoiding redundant tile repaints.