[Vala] gstreamer patch

[pancake <pancake youterm com>]

Defining default null values where possible.

We can probably extend this behaviour in other VAPIs.

diff --git a/vapi/gstreamer-0.10.vapi b/vapi/gstreamer-0.10.vapi
index 3ab5f55..cde5739 100644
--- a/vapi/gstreamer-0.10.vapi
+++ b/vapi/gstreamer-0.10.vapi
@@ -357,7 +357,7 @@ namespace Gst {
                public bool link_pads (string srcpadname, Gst.Element dest, string destpadname);
                public bool link_pads_filtered (string srcpadname, Gst.Element dest, string destpadname, 
Gst.Caps filter);
                public void lost_state ();
-               public static Gst.Element? make_from_uri (Gst.URIType type, string uri, string? elementname);
+               public static Gst.Element? make_from_uri (Gst.URIType type, string uri, string? elementname = 
null);
                public void message_full (Gst.MessageType type, GLib.Quark domain, int code, string text, 
string debug, string file, string function, int line);
                public bool post_message (owned Gst.Message message);
                public virtual unowned Gst.Clock provide_clock ();
@@ -372,7 +372,7 @@ namespace Gst {
                public void release_request_pad (Gst.Pad pad);
                public bool remove_pad (Gst.Pad pad);
                [NoWrapper]
-               public virtual unowned Gst.Pad request_new_pad (Gst.PadTemplate templ, string? name);
+               public virtual unowned Gst.Pad request_new_pad (Gst.PadTemplate templ, string? name = null);
                public bool requires_clock ();
                public bool seek (double rate, Gst.Format format, Gst.SeekFlags flags, Gst.SeekType cur_type, 
int64 cur, Gst.SeekType stop_type, int64 stop);
                public bool seek_simple (Gst.Format format, Gst.SeekFlags seek_flags, int64 seek_pos);
@@ -407,7 +407,7 @@ namespace Gst {
                public uint uri_type;
                public bool can_sink_caps (Gst.Caps caps);
                public bool can_src_caps (Gst.Caps caps);
-               public Gst.Element? create (string? name);
+               public Gst.Element? create (string? name = null);
                public static unowned Gst.ElementFactory find (string name);
                public unowned string get_author ();
                public unowned string get_description ();
@@ -419,7 +419,7 @@ namespace Gst {
                public unowned string get_uri_protocols ();
                public int get_uri_type ();
                public bool has_interface (string interfacename);
-               public static Gst.Element? make (string factoryname, string? name);
+               public static Gst.Element? make (string factoryname, string? name = null);
        }
        [CCode (ref_function = "gst_event_ref", unref_function = "gst_event_unref", cheader_filename = 
"gst/gst.h")]
        public class Event {