[rygel] core: Add setter for the serial number

[Jens Georg <jensgeorg src gnome org>]

commit c0f1d95cd0a9167243f26d9a92dcb6de9b850c55
Author: Richard Röjfors <richard rojfors gmail com>
Date:   Tue Mar 24 10:50:00 2015 +0000

    core: Add setter for the serial number
    
    Make it possible for devices to set their serial number programmatically
    instead of providing them through the description templates
    
    https://bugzilla.gnome.org/show_bug.cgi?id=746679

 src/librygel-core/rygel-description-file.vala |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/src/librygel-core/rygel-description-file.vala b/src/librygel-core/rygel-description-file.vala
index 26c1407..e837dce 100644
--- a/src/librygel-core/rygel-description-file.vala
+++ b/src/librygel-core/rygel-description-file.vala
@@ -200,6 +200,15 @@ public class Rygel.DescriptionFile : Object {
     }
 
     /**
+     * Set the Serial number of the device.
+     *
+     * @param serial is the Unique Device Name of the device.
+     */
+    public void set_serial_number (string serial) {
+        this.set_device_element ("serialNumber", serial);
+    }
+
+    /**
      * Set the DLNA caps of this root device and while taking the
      * capabilities of the plugin into account.
      *