fix(grunt): change css wrapping to prepend styles to the top of the head tag

angular.css is used by the utils.js CSS wrap operation, but ng-hide or
any other CSS styles present in angular.css cannot be overridden unless
the styles appear before the stylesheet is in place. This fix allows
for this to work

Author: matsko

lib/grunt/utils.js

@@ -85,7 +85,7 @@ module.exports = {
         .replace(/\\/g, '\\\\')
         .replace(/'/g, "\\'")
         .replace(/\r?\n/g, '\\n');
-      return "angular.element(document).find('head').append('<style type=\"text/css\">" + css + "</style>');";
+      return "angular.element(document).find('head').prepend('<style type=\"text/css\">" + css + "</style>');";
     }
   },