Implement boot-resources control

  * Allow to manage boot-resources repo
  * Allow to romove 'undefined' boot-resources repos
  * Allow to select boot-res. selections. Including for unmanaged bs repos
  * Misc: fix reuirment for non-related func
  * Fix dep's for maas_config
  * Disable rsyslog test pillar for kitchen
    - Salt always fail tests with:
      'Comment: Service rsyslog is already enabled, and is dead'

Partial-Bug: PROD-16412 (PROD:PROD-16412)

Change-Id: Idb86ffd35ef7e9fe6ce99ca5bcdd87570f8a70c4
diff --git a/README.rst b/README.rst
index 0903a6e..2f85ea0 100644
--- a/README.rst
+++ b/README.rst
@@ -64,19 +64,19 @@
           description: Test snippet
           enabled: true
           subnet: subnet1
+      boot_sources_delete_all_others: true
       boot_sources:
-        maas_mirror:
-          url: http://images.maas.io/ephemeral-v3/daily/
+        resources_mirror:
+          url: http://images.maas.io/ephemeral-v3/
           keyring_file: /usr/share/keyrings/ubuntu-cloudimage-keyring.gpg
-        local_mirror:
-          url: http://127.0.0.1/maas/images/ephemeral-v3/daily
-          keyring_file: /usr/share/keyrings/ubuntu-cloudimage-keyring.gpg
-      boot_resources:
-        bootscript1:
-          title: bootscript
-          architecture: amd64/generic
-          filetype: tgz
-          content: /srv/salt/reclass/nodes/path_to_file
+      boot_sources_selections:
+        xenial:
+          url: "http://images.maas.io/ephemeral-v3/" # should be same in boot_sources, or other already defined.
+          os: "ubuntu"
+          release: "xenial"
+          arches: "amd64"
+          subarches: '"*"'
+          labels: '"*"'
       package_repositories:
         Saltstack:
           url: http://repo.saltstack.com/apt/ubuntu/14.04/amd64/2016.3/