Improve pillar example

Add dovecot example using the services dictionary with a note that
LMTP delivery might be better.

Slight improvements about pillar example settings.

Reorder examples, put the services dictionary examples which allow
more control above the previous dovecot and submission examples.
Add a note about backwards compatibility to indicate that these
options are still supported.

pillar.example

@@ -1,23 +1,9 @@
 postfix:
   manage_master_config: True
   master_config:
-    enable_dovecot: False
+    # Preferred way of managing services/processes. This allows for finegrained
-    # The following are the default values:
+    # control over each service. See postfix/services.yaml for defaults that can
-    dovecot:
+    # be overridden.
-      user: vmail
-      group: vmail
-      flags: DRhu
-      argv: "/usr/lib/dovecot/deliver"
-
-    enable_submission: False
-    # To replace the defaults use this:
-    submission:
-      smtpd_tls_security_level: encrypt
-      smtpd_sasl_auth_enable: yes
-      smtpd_client_restrictions: permit_sasl_authenticated,reject
-
-    # Alternative way of managing services allowing for much more finegrained
-    # control over each service. See postfix/services.jinja for details.
     services:
       smtp:
         # Limit to no more than 10 smtp processes
@@ -25,6 +11,7 @@ postfix:
       # Enable oldstyle TLS wrapped SMTP
       smtps:
         enable: True
+      # Enable submission service on port 587/tcp with custom options
       submission:
         enable: True
         args:
@@ -36,6 +23,20 @@ postfix:
         chroot: True
       uucp:
 	enable: True
+      # Dovecot delivery via deliver binary. For better performance, investigate
+      # using LMTP instead: <https://wiki.dovecot.org/LMTP>
+      dovecot:
+        chroot: False
+        command: pipe
+        enable: True
+        extras: '-d ${recipient}'
+        flags: DRhu
+        type: unix
+        unpriv: False
+        user: vmail:vmail
+        argv: /usr/lib/dovecot/deliver
+      # Completely customized mail-delivery-agent entry. Will be appended to the
+      # master.cf file
       custom-mda:
         argv: /usr/local/sbin/mail-handler.py
         command: pipe
@@ -45,6 +46,23 @@ postfix:
         # Wrap the output in master.cf at 78 chars for better readability
         wrap: True
 
+    # Backwards compatible definition of dovecot delivery in master.cf
+    enable_dovecot: False
+    # The following are the default values:
+    dovecot:
+      user: vmail
+      group: vmail
+      flags: DRhu
+      argv: "/usr/lib/dovecot/deliver"
+
+    # Backwards compatible definition of submission listener in master.cf
+    enable_submission: False
+    # To replace the defaults use this:
+    submission:
+      smtpd_tls_security_level: encrypt
+      smtpd_sasl_auth_enable: yes
+      smtpd_client_restrictions: permit_sasl_authenticated,reject
+
   enable_service: True
   reload_service: True