Preconfigure allowed_hosts.conf style files for plugins

set the variable vdr_allowed_hosts (must be a list of IPs/IP ranges) to preconfigure all host-
or ip-range based access options.

At the moment this applies to:
 - svdrphosts.conf
 - xineliboutput's allowed_hosts.conf (and the plugin's ARGSDIR configuration file)
 - vnsiserver's allowed_hosts.conf
 - streamdev-server's streamdevhosts.conf

It is possible to override host settings for individual services by
setting up extra lists for the following variables:
 - vdr_svdrphosts
 - xineliboutput_allowed_hosts
 - vnsiserver_allowed_hosts
 - streamdev_server_allowed_hosts

roles/vdr/templates/generic_allowed_hosts.conf.j2

@@ -0,0 +1,22 @@
+{{ ansible_managed | comment }}
+# This file describes a number of host addresses that
+# are allowed to connect to the {{ vdr_service }}
+# running with the Video Disk Recorder (VDR) on this system.
+#
+# Syntax:
+#
+# IP-Address[/Netmask]
+#
+# Examples:
+#
+# 192.168.100.0/24     # any host on the local net
+# 204.152.189.113      # a specific host
+{% if vdr_service == 'streamdev-server' %}
+# 239.255.0.0/16       # uncomment for IGMP multicast streaming
+{% endif %}
+# 0.0.0.0/0            # any host on any net (USE THIS WITH CARE!)
+
+127.0.0.1              # always accept localhost
+{% for host_or_subnet in allowed_hosts %}
+{{ host_or_subnet }}
+{% endfor %}

roles/vdr/templates/svdrphosts.conf.j2

@@ -7,14 +7,12 @@
 #
 # IP-Address[/Netmask]
 #
+# Examples:
+# 192.168.100.0/24     # any host on the local net
+# 204.152.189.113      # a specific host
+# 0.0.0.0/0            # any host on any net (USE THIS WITH CARE!)
 
-127.0.0.1             # always accept localhost
-#192.168.100.0/24     # any host on the local net
-#204.152.189.113      # a specific host
-#0.0.0.0/0            # any host on any net (USE THIS WITH CARE!)
-
-{% if vdr_svdrphosts is defined %}
-{% for host_or_subnet in vdr_svdrphosts %}
+127.0.0.1              # always accept localhost
+{% for host_or_subnet in svdrphosts %}
 {{ host_or_subnet }}
 {% endfor %}
-{% endif %}

roles/vdr/templates/xineliboutput.conf.j2

@@ -0,0 +1,13 @@
+#
+# Command line parameters for vdr-plugin-xineliboutput
+#
+# For more details see:
+#   - /usr/share/doc/vdr-plugin-xineliboutput/README.Debian
+#   - `vdr --help -Pxineliboutput`
+#   - /usr/share/doc/vdr-plugin-xineliboutput/README
+#
+[xineliboutput]
+--local=none
+--primary
+--remote={{ "" if allowed_hosts else "127.0.0.1" }}:37890
+--truecolor