Teach HALAPIResource to handle relative root path

Hyperagent Ajax queries will use jQuery's Ajax implementation rather
than Angular's $http (which automatically prepends the relative root
path, see f148c824).

Bug # 15314

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Test HALAPIResource relative root path handling

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Fix missing DetailsTabOverviewController dependency

Signed-off-by: Alex Coles <alex@alexbcoles.com>