[texdoc] Some small bugs and more

[Karl Berry]

    In that situation, texdoc will ask something like
            Do you mean "FOOBAZ"? (y/N)

I think it should just default to using the fuzzy results instead of
asking anything, when no regular search results are found. The whole
idea of texdoc is convenience, so why not? There could be an option
  --fuzzy=yes|no|interact
(plus config file options, etc., etc.) for users to specify if they care.

Although I guess the options could get more complicated, since there's
also the question of what the cutoff for the distance should be.
Well, you get the idea :).

Thanks,
Karl