Ignore trailing question marks in question-like commands (e.g. seen, whatis)

[mlncn]

For example:

@seen fred?

Should give the same result as:

@seen fred

And:

@whatis truth?

Should give the same result as:

@whatis truth

[mlncn]

CC @wolcen

[jlu5]

This seems fairly arbitrary and I don't think it makes sense for most commands. I certainly wouldn't want commands like echo or bold for example to suddenly start stripping characters.

[mlncn]

@GLolol OK good point. Only for commands that people would naturally think of as a question.