API urls - support both with/without trailing slashes

[rlskoeser]

Consider supporting API endpoints with and without trailing slashes (e.g., via redirect from whichever is considered the non-canonical version of a given API url). This would make it easier and less error prone for people experimenting with the API.

[rlskoeser]

The trailing slashes could possibly account for some of the unexpected 200 OK empty responses I got when experimenting with the API. I don't know if your xqm code would interpret the trailing slash as an empty identifier in some cases or just ignore it entirely.