Support user lookup via API using username
At the moment the API only supports lookups of Users and Groups via a numeric ID AFAIK. This leads to writing code that first searches for a user, then uses the ID from the first result to lookup more things related to that user. The entire approach seems quite cumbersome to me and it'd be nice to be able to just lookup a user by a GET to "/users/foo" instead.
Edited by Mark Fletcher