ddns-scripts: Add more services and minor changes

- add support of knsupdate (update_nsupdate.sh
- url update easydns.com
- add some service answers
- alphabetic reorder services files for easier reading
- rename services/provider (Makefile postinst handle /etc/config/ddns)
 -- freedns.afraid.org -> afraid.org
 -- free.editdns.net -> editdns.net
 -- domains.google.com -> google.com
 -- spdns.de -> spdyn.de
 -- strato.de -> strato.com
- new provider (looking in deep into https://sourceforge.net/projects/inadyn-mt project)
 -- dyn.com (= dyndns.org)
 -- ddnss.de
 -- dhis.org
 -- dnspark.com (IPv4 only)
 -- dynsip.org (IPv4 only)
 -- dynv6.com
 -- joker.com (IPv4 only)
 -- loopia.com (= loopia.se)
 -- sitelutions.com (IPv4 only)
 -- system-ns.com (IPv4 only)
- new provider (looking in deep into /etc.defaults/ddns_provider.conf file for Synology DiskStation published at https://gist.github.com/ntrepid8/6653274)
 -- able.or.kr (IPv4 only)
 -- ddo.jp (IPv4 only)
 -- dnsmadeeasy.com (IPv4 only)
 -- oray.com (IPv4 only)
- new provider (looking in deep into https://github.com/ipfire/ddns project)
 -- all-inkl.com
 -- desec.io
 -- domopoli.de (IPv4 only)
 -- opendns.com (IPv4 only)
 -- udmedia.de
 -- xlhost.de (IPv4 only)
- new provider (looking in deep into https://github.com/yaddns/yaddns project )
 -- dyndns.it (IPv4 only)

Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

net/ddns-scripts/files/dynamic_dns_updater.sh

@@ -13,27 +13,33 @@
 # variables in big chars beginning with "__" are local defined inside functions only
 # set -vx  	#script debugger
 
-. /usr/lib/ddns/dynamic_dns_functions.sh	# global vars are also defined here
+. $(dirname $0)/dynamic_dns_functions.sh	# global vars are also defined here
 
 [ $# -lt 1 -o -n "${2//[0-3]/}" -o ${#2} -gt 1 ] && {
-	echo -e "\n  ddns-scripts Version: $VERSION"
-	echo -e "\n  USAGE:"
-	echo    "  $0 [OPTION]"
-	echo    "  [OPTION]	  '-V' or '--version' display version and exit"
-	echo -e "\n  $0 [SECTION] [VERBOSE_MODE]\n"
-	echo    "  [SECTION]      - service section as defined in /etc/config/ddns"
-	echo    "  [VERBOSE_MODE] - '0' NO output to console"
-	echo    "                   '1' output to console"
-	echo    "                   '2' output to console AND logfile"
-	echo    "                       + run once WITHOUT retry on error"
-	echo    "                   '3' output to console AND logfile"
-	echo    "                       + run once WITHOUT retry on error"
-	echo -e "                       + NOT sending update to DDNS service\n"
+	local __ME=$(basename $0)
+	cat << EOF
+ddns-scripts Version: $VERSION
+
+Usage:
+  $__ME -V         display version and exit
+  $__ME --version  display version and exit
+
+  $__ME <SECTION> <VERBOSE_MODE>
+  <SECTION>        service section as defined in /etc/config/ddns
+  <VERBOSE_MODE>   '0' NO output to console
+                   '1' output to console
+                   '2' output to console AND logfile
+                       + run once WITHOUT retry on error
+                   '3' output to console AND logfile
+                       + run once WITHOUT retry on error
+                       + NOT sending update to DDNS service
+
+EOF
 	exit 1
 }
 
 [ "$1" = "-V" -o "$1" = "--version" ] && {
-	echo -e "ddns-scripts $VERSION\n"
+	printf %s\\n "ddns-scripts $VERSION"
 	exit 0
 }