+ some generic mime types item.rb

[127]

+mime-types:
eot, mp3, mp4

[skoji]

Thanks for PR. But there are some problems in commit ba7d7fe .

1. Item#guess_mimetypes do not return value.
   It just loops over @@mime_types and just 'puts' the matched result.
   Should be return instead of puts.
2. end missing, so whole library will not work.

Besides, I am not sure to add method Item#add_mime_type. I think there is no need to add special mimetype to guess_mimetypes. You can specify any mimetype explicitly with add_item.

I'll merge this PR by cherry-picking the commit a109973 .

[127]

Sorry about ba7d7fe it's an error — pushed wrong sample.
I'm trying to take away the whole mime types stuff to a single standalone class now for my own purpose. Will pull request it later as a proposal.