When looking up a types, check hasOwnProperty

[thejh]

When looking up a types, check hasOwnProperty - we don't want to pretend that __defineGetter__ is a valid file extension whose MIME type is a function.

[broofa]

Is this causing problems in real code, or is this merely a theoretical concern at this point?

[thejh]

Well, e.g. this HTTP response looks somewhat unclean: https://gist.github.com/84464a405a7018066428 - however, I don't know any way to exploit this or a case in which this causes much trouble.

[broofa]

Seems like the tradeoff is the microscopically small difference in code legibility and size .vs. the even smaller chance this will ever matter in real-world code. I don't feel strongly enough to want to change things, but I'll leave this open if anyone else wants to weigh in.

[broofa]

Resolving in #24