- Add systemd support.

- Improve adjusting /etc/postfix/main.cf.

conf/install_update_dovecot.conf.sample

@@ -23,6 +23,13 @@ _version=2.2.28
 _pigeonhole=dovecot-2.2-pigeonhole-0.4.16
 
 
+# - Install dovecot with systemd support
+# -
+# - Defaults to 'true' if systemd is present, otherwise to 'false'
+# -
+systemd_support=""
+
+
 # - postmaster_address
 # -
 # - Example: