Feature Request: Expose more parsing options in html_read
I am trying to parse some HTML and would love to have `converters` (https://github.com/pydata/pandas/blob/master/pandas/io/parsers.py#L1582-L1586) exposed to the `read_html` function.  

Is there a reason why more parsing/all parsing options aren't exposed to `TextParser` at https://github.com/pydata/pandas/blob/master/pandas/io/html.py#L631-L634 ?  

If not, would it be of interest to have a PR that adds this functionality?
