merge master and upstream

Signed-off-by: arcticlion <david.malan@aol.com>
add working\ with\ style\ sheets.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Funciton getStyleSheet in working\ with\ style\ sheets.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Usage of document.styleSheets[0].cssRules[0] in working\ with\ style\ sheets.js

Signed-off-by: arcticlion <david.malan@aol.com>
修改样式信息 in working\ with\ style\ sheets.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Function of insertRule in working\ with\ style\ sheets.js

Signed-off-by: arcticlion <david.malan@aol.com>
write a Function of deleteRule in working\ with\ style\ sheets.js

Signed-off-by: arcticlion <david.malan@aol.com>
Merge master and dev
update README.md

Signed-off-by: arcticlion <david.malan@aol.com>
Merge pull request #11 from arcticlion/master

Keep on pulling request