Adds image and mask features, fixes clippath
Reduces amount of used memory during PNG creation.
Merge pull request #5162 from yurydelendik/pramodhkp-fixupgstate2

[SVG] Reduces amount of used memory during PNG creation.
only convert in IE9 if the requested responseType is actually an arraybuffer, otherwise just return the responseText. That way the compatibility.js does not break other frameworks like angular that not always want an array from xhr requests.