Switch config file.recurse to clean by default and tell it to ignore _*

Salt writes it's schedule file to /etc/salt/{minion,master}.d/_schedule.conf

We don't want to stomp all over Salt's files, but we do want a pristine
starting point to lay down our managed config. So we use clean: True on the
file.recurse call, but we tell it to ignore files that start with an _

We have to rename the current config file (_defaults.conf) because it will be
ignored by the rule that ignores Salt's _* config files.

This also means we need to clean up old config files (_defaults.conf) and
restart the service if we cleaned it up.

salt/defaults.yaml

   salt_cloud: salt-cloud
   salt_api: salt-api
   salt_ssh: salt-ssh
-  clean_config_d_dir: False
+  clean_config_d_dir: True
 
   master:
     gitfs_provider: gitpython

salt/master.sls

     - template: jinja
     - source: salt://salt/files/master.d
     - clean: {{ salt_settings.clean_config_d_dir }}
+    - exclude_pat: _*
   service.running:
     - enable: True
     - name: {{ salt_settings.master_service }}
       - pkg: salt-master
 {% endif %}
       - file: salt-master
+      - file: remove-old-master-conf-file
+
+# clean up old _defaults.conf file if they have it around
+remove-old-master-conf-file:
+  file.absent:
+    - name: /etc/salt/master.d/_defaults.conf

salt/minion.sls

     - template: jinja
     - source: salt://salt/files/minion.d
     - clean: {{ salt_settings.clean_config_d_dir }}
+    - exclude_pat: _*
     - context:
         standalone: False
   service.running:
       - pkg: salt-minion
 {% endif %}
       - file: salt-minion
+      - file: remove-old-minion-conf-file
+
+# clean up old _defaults.conf file if they have it around
+remove-old-minion-conf-file:
+  file.absent:
+    - name: /etc/salt/minion.d/_defaults.conf

salt/standalone.sls

     - template: jinja
     - source: salt://salt/files/minion.d
     - clean: {{ salt_settings.clean_config_d_dir }}
+    - exclude_pat: _*
     - context:
         standalone: True
   service.dead:
       - pkg: salt-minion
 {% endif %}
       - file: salt-minion
+
+# clean up old _defaults.conf file if they have it around
+remove-old-standalone-conf-file:
+  file.absent:
+    - name: /etc/salt/minion.d/_defaults.conf