Squashed commit of the following:

commit 2701c8868e
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Oct 5 11:01:57 2014 +0200

    ddns-scripts: Added support for custom update scripts

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

commit e07ecb90fa
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Oct 5 11:00:11 2014 +0200

    ddns-scripts: Added support for custom update scripts

    Added support for custom update scripts with new option update_script.
    function get_service_url() renamed to get_service_data() and extended to detect scripts inside service / service_ipv6 for later use
    function send_update() modified to support custom update scripts.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit 39e41b2151
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Oct 5 10:52:44 2014 +0200

    ddns-scripts: Added support for custom update scripts

    Added support for custom update scripts with new option update_script
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit 33f264768e
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Oct 5 10:48:21 2014 +0200

    ddns-scripts: Insert description for NEW option update_script

    Insert description for NEW option update_script
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit 6f6a60244d
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Oct 5 10:43:52 2014 +0200

    ddns-scripts: Update PKG_RELEASE

    Update_PKG_RELEASE to reflect changes
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

Squashed commit of the following:

commit fc1d42f069
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 18:01:43 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

commit 731f9b4df0
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:59:25 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    personal helper script to create hashes for CA-Certificates for Wget and cURL using https protocol without errors.

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit df8f6c9d5d
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:56:05 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    rewritten

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit 50cdf5acb9
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:54:40 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    rewritten

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit b1d650a345
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:52:52 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    not needed in this version

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit 9532114b03
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:51:39 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    same function as existing services file but used for IPv6

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit a636bc25c6
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:46:56 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    New file explaining availible parameters.

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.
    Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>

commit 52332354fc
Author: Christian Schoenebeck <christian.schoenebeck@gmail.com>
Date:   Sun Sep 21 17:44:45 2014 +0200

    [ddns-scripts] Update to Version 2.0.1-1

    Sorry GitHub web interface only supports single commits that will be summarized into one pull request.

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

To be consistent with other services only start via hotplug if enabled.
Now full functionality of /etc/init.d/ddns enable/disable start/stop

Optimization: Include script only if needed

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

Hotplug script will start service for each interface.
To prevent duplicates and in general must not start on boot.

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

Signed-off-by: Nikos Mavrogiannopoulos <nmav@gnutls.org>