Add "L3", "L4", "L5" and "L6" about CSS3

L3: new element of CSS3
L4: types of background with CSS3
L5: text manipulation with CSS3
L6: 2D manipulation on elements in HTML with CSS3
Upgraded "L7" and "L8", add "L9"

Upgraded “L7” and “L8” with transform and animation operations.
“L9”: about User Interface (resize)
Add "L10" about Drag&Drop in HTML5

“L10”: operation of drag&drop in HTML5, with CSS and JS