Move more autocomplete logic from web to api

[rwstauner]

There was discussion on irc today about porting the autocomplete query from web to api.

I was a little surprised to find #139

So apparently autocomplete is available on both sites but the web endpoint adds extra goodness that produces better results.

Moving more of the logic makes sense, and would also give us jsonp (another feature requested on irc today).

[monken]

Do you have an example? I'm pretty sure I moved everything to the api. There are some leftovers in the metacpan-web repo that are not being used anymore

[rwstauner]

@tsibley was asking on irc
and specifically said http://api.metacpan.org/v0/search/autocomplete?q=App::Prove didn't return good results
compared to the web one which did some more stuff but didn't support jsonp

[oalders]

He also said http://api.metacpan.org/v0/search/autocomplete?q=App&q=Prove wasn't much better. We're not using the api's autocomplete from metacpan-web yet, are we?

[tsibley]

metacpan-web uses a custom File search for autocomplete requests like
https://metacpan.org/search/autocomplete?q=App::Prove. Code at
https://github.com/CPAN-API/metacpan-web/blob/master/lib/MetaCPAN/Web/Model/API/Module.pm#L52