fix the regular expression that turns camel-case properties to lower-…

…case ones for IE9. Fixes #8346

src/css.js

@@ -3,7 +3,7 @@
 var ralpha = /alpha\([^)]*\)/i,
 	ropacity = /opacity=([^)]*)/,
 	rdashAlpha = /-([a-z])/ig,
-	rupper = /([A-Z])/g,
+	rupper = /([A-Z]|^ms)/g,
 	rnumpx = /^-?\d+(?:px)?$/i,
 	rnum = /^-?\d/,