Merged r6187 from trunk.
Mitigates vulnerability in API authentication introduced in r3218.
Makes custom queries available through the REST API (#5737).
Fixes version url.
Makes relations resource shallow (#7366).
Makes versions resource shallow (#7403).
Adds breadcrumb on all wiki page views.
Removed leading dash in ruby code.
Adds REST API for versions (#7403).
Adds support for GET on /issues/:issue_id/relations (#7366).