v1.5.0

The main feature in this release are performance improvements to the UriInterpolator (#197 by @danilbykov).

There is a binary incompatible change: the internals of the UriInterpolator (tokenizers and parsers) are now private, with changed implementations. However, as these were always intended to be used only internally (and made public by omission, rather than on purpose), and I don't think anybody is using them directly, hopefully this won't cause any disruption to our users.