Prevent default behavior of keydown event to avoid having the screen scrolling up and down
Fix bug of disabling wrong keydown events
Merge branch 'master' into layout

Conflicts:
	js/app.js
Add link to share game completion on social network
Restructure the layout
Define pause and resume behavior
Create template folder and move html template for game-won modal dialog there
Create the guide as a template and load it as a modal dialog
Fix the link to target state image to be relative URL
Create a separate image to show target state
Fix link to target state image in the guide template
Resize images to reduce load time
Create a separate favicon file
Define icon file of different sizes
Move meta before link in the header so that favicon can be showed when the web app is added on homescreen
Fix wrong target state image. Update the favicon as well
Use the screenshot of the target state for README.md
Move favicon to root folder
Define viewport with device-width, no scale
Add  to update number of seconds