* src/sql/upgrade-7.sql: New file.
* Makefile.am: Add it.
* src/cuirass/base.scm (create-build-outputs): New procedure,
(build-packages): call it,
(process-spec): add the new spec argument and pass it to create-build-outputs.
* src/cuirass/database.scm (db-add-build-product, db-get-build-product-path,
db-get-build-products): New exported procedures.
* src/cuirass/http.scm (respond-static-file): Move file sending to ...
(respond-file): ... this new procedure,
(url-handler): add a new "download/<id>" route, serving the requested file
with the new respond-file procedure. Also gather build products and pass them
to "build-details" for "build/<id>/details" route.
* src/cuirass/templates.scm (build-details): Honor the new "products" argument
to display all the build products associated to the given build.
* src/schema.sql (BuildProducts): New table,
(Specifications)[build_outputs]: new field.
* tests/database.scm: Add empty build-outputs spec.
* tests/http.scm: Ditto.
* examples/guix-jobs.scm: Ditto.
* examples/hello-git.scm: Ditto.
* examples/hello-singleton.scm: Ditto.
* examples/hello-subset.scm: Ditto.
* examples/random.scm: Ditto.
* doc/cuirass.texi (overview): Document it.