bitbake: toastergui: provide download file capability

We add, for the localhost environments, the capability to
download build artifacts. This is a pontentially dangerous API,
because it gives unrestricted read access to the build environment
file system - do not expose the functionality directly to the
web layer, but use filtering/translation code, such as
exemplified in the build_artifact view.

The capability for remote build environments is dependent
on bug 6835, as to use the collect storage as intermediary
storage for serving files.

[YOCTO #6834]

(Bitbake rev: 5fce7f6e83c6143244faa9618b7ed20c1106e08f)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/toastergui/templates/task.html

@@ -28,7 +28,11 @@
             <i class="icon-question-sign get-help" title="Path the task log file"></i> Log file
         </dt>
         <dd>
+	{% if MANAGED %}
+            <code><a href="{% url 'build_artifact' build.pk 'tasklogfile' task.pk %}" target="_blanc">{{task.logfile}}</a></code>
+	{% else %}
             <code>{{task.logfile}}</code>
+	{% endif %}
         </dd>
 	{% endif %}
         {# show stack trace for failed task #}