Fix broken redirects

Dependencies

• [2] AWMM5OGV Use delete instead of delete_all
• [3] UOINKJ2J Add an action to cancel all builds in a jobset eval
• [4] ZWCTAZGL added newsitems, added some admin options to clear various caches.
• [5] RXSEJG7W Do not delete builds when clearing the queue. Fixes #8.
• [6] QDCXMFDQ Don't print to stdout
• [7] DETQRBBR clear_queue_non_current: Don't use isCurrent
• [8] KEBKLMYZ clear-queue-non-current: Work around PostgreSQL query optimizer stupidity
• [9] R6B5CAFF Let Builds.timestamp refer to the time the build was added
• [10] 5NSQUYBS Clear failed builds etc.: Redirect back to the referrer
• [11] FXW2UR7F initial bzr support
• [12] 67NFGL7D add links in admin page to clear queue (all non-running builds, and all non-running old (non-current) builds)

Change contents

• replacement in src/lib/Hydra/Controller/Admin.pm at line 42
  [3.187]→[4.0:57](∅→∅),[4.348]→[4.0:57](∅→∅),[4.624]→[4.0:57](∅→∅),[4.144]→[4.0:57](∅→∅)
  − $c->res->redirect($c->request->referer // "/admin");
  [3.187]

  [4.258]
  + $c->res->redirect($c->request->referer // "/");
• replacement in src/lib/Hydra/Controller/Admin.pm at line 49
  [4.448]→[4.58:115](∅→∅)
  − $c->res->redirect($c->request->referer // "/admin");
  [4.448]

  [4.482]
  + $c->res->redirect($c->request->referer // "/");
• replacement in src/lib/Hydra/Controller/Admin.pm at line 60
  [2.258]→[4.116:173](∅→∅),[4.91]→[4.116:173](∅→∅)
  − $c->res->redirect($c->request->referer // "/admin");
  [2.258]

  [4.1143]
  + $c->res->redirect($c->request->referer // "/");