ENH: allow to_html and to_latex to take a path for their first argument

[cpcloud]

No description provided.

[jreback]

not so sure that to_string should take this argument; its for a pure string rep, while to_csv has all the options for outputing to a file (eg. specialized nan rep, separators, etc)

@y-p ?

[cpcloud]

Yeah that's right. More things to maintain for u guys and probably would be confusing for new users. Will take out

[y-p]

Agree with jeff, doesn't belong in to_string.

I would opt for isinstance(basestring) here, 'better to ask forgiveness" not withstanding.
to_html(FooObject) should not try to open(FooObject), it should give a sane error message.

[cpcloud]

@y-p indeed, thanks.