write a Method of getRelatedTarget in eventUtil.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Usage of getRelatedTarget in eventUtil.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Method of getButton in eventUtil.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Usage of getButton in eventUtil.js

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

Signed-off-by: arcticlion <david.malan@aol.com>
添加鼠标易访问性tips in mouse.js

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

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