Proper stream type bitflags

[yupferris]

Ran into issues with these implementing/testing a fix for #12. They need to be proper bitflags so they can be combined and all valid values can be represented.

[yupferris]

While this may also lead to some invalid combinations being represented, I don't think it's a problem as we're still guaranteed to be memory-safe, and the fact that we can propagate runtime errors covers that. I think that's more of an issue of the original API and one we shouldn't be too concerned about tackling, unless it ends up being pretty easy. Will have to see.

[mitchmindtree]

Ahh yep (I think I wrote this before I knew what bitflags were). There's a decent crate for bitflags here.

[mitchmindtree]

Going to look into fixing this now.

[yupferris]

awesome!

[yupferris]

Fixed in #27