add mouse.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Usage of screenX&screenY in mouse.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Usage of shiftKey,ctrlKey... in mouse.js

Signed-off-by: arcticlion <david.malan@aol.com>
添加相关元素的概念，涉及mouseover,mouseout in mouse.js

Signed-off-by: arcticlion <david.malan@aol.com>