add support for CSS3 basic box model

after/syntax/css/css3-box.vim

@@ -0,0 +1,5 @@
+syn match cssBoxProp contained "\<overflow-\(style\|x\|y\)\>"
+syn match cssBoxProp contained "\<rotation\(-point\)\=\>"
+syn keyword cssBoxAttr contained scrollbar panner move marquee
+syn match cssBoxAttr contained "\<ruby\(-\(base\(-group\)\=\|text\(-group\)\=\)\)\=\>"
+syn match cssBoxAttr contained "\<no-\(display\|content\)\>"

after/syntax/css/css3-properties.vim

@@ -1 +0,0 @@
-syn match cssBoxProp contained "\<overflow-\(x\|y\)\>"