Update GStreamer gir files

This is based on bd534af999ca596ba71c4ab869de0837403fa15b.

GES-1.0.gir

@@ -6466,7 +6466,7 @@ it has been set.</doc>
             <doc xml:space="preserve">A #GESPipeline</doc>
             <type name="Pipeline" c:type="GESPipeline*"/>
           </instance-parameter>
-          <parameter name="timeline" transfer-ownership="full">
+          <parameter name="timeline" transfer-ownership="none">
             <doc xml:space="preserve">The timeline to set for @pipeline</doc>
             <type name="Timeline" c:type="GESTimeline*"/>
           </parameter>
@@ -8551,7 +8551,7 @@ that you avoid adding tracks to timelines that already contain clips.</doc>
             <doc xml:space="preserve">The #GESTimeline</doc>
             <type name="Timeline" c:type="GESTimeline*"/>
           </instance-parameter>
-          <parameter name="track" transfer-ownership="full">
+          <parameter name="track" transfer-ownership="none">
             <doc xml:space="preserve">The track to add</doc>
             <type name="Track" c:type="GESTrack*"/>
           </parameter>

Gst-1.0.gir

@@ -18515,7 +18515,7 @@ and make a copy if you want to modify it or store it for later use.</doc>
             <type name="Event" c:type="GstEvent*"/>
           </instance-parameter>
           <parameter name="collection" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
-            <doc xml:space="preserve">pointer to store the collection</doc>
+            <doc xml:space="preserve">pointer to store the collection.</doc>
             <type name="StreamCollection" c:type="GstStreamCollection**"/>
           </parameter>
         </parameters>

GstGL-1.0.gir

@@ -1559,7 +1559,7 @@ active.
 @context_type must not be %GST_GL_PLATFORM_NONE or %GST_GL_PLATFORM_ANY
 @available_apis must not be %GST_GL_API_NONE or %GST_GL_API_ANY</doc>
-        <return-value transfer-ownership="full">
+        <return-value transfer-ownership="full" nullable="1">
           <doc xml:space="preserve">a #GstGLContext wrapping @handle</doc>
           <type name="GLContext" c:type="GstGLContext*"/>
         </return-value>