Option to preserve new lines

[eseiver]

Sometimes when I pass in a string, I want an option to preserve new line information, so I'd like calling no_blank_parser to be an option that defaults to True.

[mpacer]

feel free to make a PR, happy to help guide you if you'd prefer that.

[mpacer]

I believe there was a complication related to this where it didn't make sense to instantiate a separate version of the parser for each instance of the XML object. We could just create two parsers ahead of time that will be globally available for all the XML instances regardless, and then you choose the parser based on the value of the option.