Deprecate XMLReader variant of DocumentFactory.createDocument, add setXMLReader

[carlosame]

Interface DocumentFactory in the dom module has the following method variant:

echosvg/echosvg-dom/src/main/java/io/sf/carte/echosvg/dom/util/DocumentFactory.java

Line 80 in a42e24d

Document createDocument(String ns, String root, String uri, XMLReader r) throws IOException;

which is confusing because only allows the usage of the XMLReader via the document URI retrieval.

That method should be deprecated, and instead a new setXMLReader(XMLReader) could be added. That way, one can specify an XMLReader to be used by the factory, regardless of the chosen input variant (stream, reader or URI retrieval).