- As opposed to the issue `id` that was previously being used.
- This brings the API routes closer to the web interface's routes.
- This is specific to API v4.
New endpoints are:
POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/time_estimate"
POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/reset_time_estimate"
POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/add_spent_time"
POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/reset_spent_time"
GET :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/time_stats"