(html obj) BRL syntax
Returns a string that is a suitable representation of obj for
an HTML page. If obj is null, brl-null-value is
returned. If obj is a table, an HTML table is returned.
Otherwise brl-string is used to convert obj to a
string, and within that string certain characters (<, >, ")
are converted into the appropriate HTML entities.
(html "<santa@northpole.org>")
returns "<santa@northpole.org>"