Limit "auto-clicks" per second

Fixes #3.
The auto-clickers now stop auto-clicking after a number of auto-clicks per
second. When this limit is hit, the number of mushrooms per auto-click is
increased instead.
Create "button" CSS-class

Creates a general purpose CSS-class for use with buttons
Add reset button

Fixes #6.
Adds a button that resets the mushroom counter, and data related to
auto-clickers.

Conflicts:
	src/script.js
Make use of jQuery

Fixes #8.
Use jQuery based code to handle events and interactivity.
Use one timer event for clickers

Fixes #12.
Only one clicker event is in place at any one time.
The interval is decreased with each added clicker.

Conflicts:
	src/script.js
Use jquery-cookie library

Includes the jquery-cookie 3rd party library
For easier cookie management with jQuery
Add manual save functionality.

Adds a button for the user to manually save the game.
Add autosave

Fixes #5.
Adds auto-save functionality.