Clear failed builds etc.: Redirect back to the referrer

Dependencies

• [2] RXSEJG7W Do not delete builds when clearing the queue. Fixes #8.
• [3] JARRBLZD Bootstrapify the Hydra forms (except the project and jobset edit pages)
• [4] FXW2UR7F initial bzr support
• [5] ZWCTAZGL added newsitems, added some admin options to clear various caches.
• [6] 67NFGL7D add links in admin page to clear queue (all non-running builds, and all non-running old (non-current) builds)
• [7] QT4FO2HP refactored admin controller, using chains, to avoid using requireadmin on each endpoint
• [8] 6KJXJB7N qualify ordery_by clauses when necessary, remove unnecessary order_by's, reported by Ludo, resulted in errors in sqlite
• [9] MOX7XJ2E Merge the BuildSchedulingInfo table into the Builds table

Change contents

• replacement in src/lib/Hydra/Controller/Admin.pm at line 325
  [2.144]→[3.225:258](∅→∅),[3.768]→[3.225:258](∅→∅),[3.225]→[3.225:258](∅→∅)
  − $c->res->redirect("/admin");
  [2.144]

  [3.258]
  + $c->res->redirect($c->request->referer // "/admin");
• edit in src/lib/Hydra/Controller/Admin.pm at line 331
  [3.397]→[3.397:398](∅→∅)
  −
• replacement in src/lib/Hydra/Controller/Admin.pm at line 332
  [3.448]→[3.448:482](∅→∅)
  −

  − $c->res->redirect("/admin");
  [3.448]

  [3.482]
  + $c->res->redirect($c->request->referer // "/admin");
• replacement in src/lib/Hydra/Controller/Admin.pm at line 351
  [3.91]→[3.1110:1143](∅→∅),[3.1110]→[3.1110:1143](∅→∅)
  − $c->res->redirect("/admin");
  [3.91]

  [3.1143]
  + $c->res->redirect($c->request->referer // "/admin");