Initial pre-release

I'm calling this a very low number for the time being, although I'm relatively sure the API is ready for use as-is. My biggest reason for not calling it something larger is that I'll probably add more classes before I'm ready to declare a 1.0, and I'd like to make my validation stronger before reaching 1.0.

Key points about this release: a given uri object can be declared as const without losing access to any of its functionality, since I've made all of its public API const. This was on purpose; replacing components of a URI feels unstable, and personally I'd prefer to construct a new URI with components replaced than potentially corrupt another code segment's known URI. (Yes, this does go against having the copy constructor and copy assignment operator. Use them with caution.)

Now that I've built enough of a uri object, I'll start using it in the project I started (and realized I needed it for, you can see the initial stub of it in my first commits) and begin to see where the pain points are in this implementation. Changes may result from that need. Have fun!