URI normalization #1623
Description
In the #1618 review discussion, I noticed that we may not be doing the right thing regarding URI normalization. RFC 3987 says,
Applications using IRIs as identity tokens with no relationship to a protocol MUST use the Simple String Comparison (see section 5.3.1). All other applications MUST select one of the comparison practices from the Comparison Ladder (see section 5.3
JSON Schema describes our use of IRIs as identity tokens, not locators, which means implementations should limit themselves to Simple String Comparison. That's not what our spec currently says. It says to use the normalization procedure defined in 5.3, which isn't quite correct either. We'd need to be more specific about which comparisons to use. For example, we wouldn't require scheme-based or protocol-based normalization because it would be too onerous a requirement for implementers to implement scheme-based requirements for any scheme they might encounter.