remove_blank_text and other options of XMLParser missing

The library doesn't provide a way to remove blank text. Using the basic lxml library: ```python from lxml import etree PARSER = etree.XMLParser(remove_blank_text=True) res = etree.XML(string, parser=PARSER) ``` This is the same for any option mentionned in #23. These are important features that should be supported . I tried to use ``XMLParser` from the original libary with the `XML()` of this one, I also tried to use `DefusedXMLParser`. This simply doesn't seem possible. Can you provide an example on how to access these features? Thank you.