Path parameters allow undocumented formats

[sfackler]

The HTTP path parser appears to allow three different parameter syntaxes: {argName}, {argName:.*} and {argName:.+}: https://github.com/palantir/conjure/blob/master/conjure-core/src/main/java/com/palantir/conjure/defs/validator/HttpPathValidator.java#L42-L45

However, only the first of these is actually discussed in the specification: (https://github.com/palantir/conjure/blob/master/docs/spec/conjure_definitions.md#path-parameters

[ferozco]

I remember seeing an internal discussion where the syntax you provide was explicitly omitted from the spec (but left in the code) because we wanted to remove it but did not want to break current users. @uschi2000 may have more context here

[sfackler]

It is in conjure-java's example service, which is where I noticed it: https://github.com/palantir/conjure-java/blob/develop/conjure-java-core/src/test/resources/example-service.yml#L162

Probably worth logging a deprecation warning at least if we want to get rid of it?