Misc: Drop support for older browsers; update support comments

That includes Opera 12.x, Firefox<29, Safari<6.0 and some hacks
for old Blackberry.

Closes gh-1820
Refs gh-1815

src/css.js

@@ -34,7 +34,7 @@ var
 		fontWeight: "400"
 	},
 
-	cssPrefixes = [ "Webkit", "O", "Moz", "ms" ];
+	cssPrefixes = [ "Webkit", "Moz", "ms" ];
 
 // Return a css property mapped to a potentially vendor prefixed property
 function vendorPropName( style, name ) {