[SVGMobile12] parseXML method description has some wording that could be improved

The second paragraph starts with:  "The purpose of the document parameter".  But 
this method has no parameter named "document".  Similar issue in the last 
sentence of this paragraph.

Step 3 has "mentionned", which should be "mentioned".

I'm not sure what Step 4 means.  parseXML returns a Node.  What needs to be cast 
to Element and why, exactly?  Note that importNode returns a Node...

The description of the "contextDoc" parameter says: "The Document object in the 
context of which to produce the parsing.".  I don't think the parsing is being 
"produced", exactly.  Perhaps "perform"?

-Boris