ChatView : add button to send basic invitation.

- an "invite" button is added to the chatview, click on it, will request
the daemon to send a contact request to the uri of the contact shown.

Change-Id: I3959eb5d4ac153d54762ee80ea2f68a766e730a7
Reviewed-by: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
diff --git a/ui/chatview.ui b/ui/chatview.ui
index 308876a..1ffad00 100644
--- a/ui/chatview.ui
+++ b/ui/chatview.ui
@@ -54,6 +54,16 @@
           </packing>
         </child>
         <child>
+          <object class="GtkButton" id="button_send_invitation">
+            <property name="visible">True</property>
+            <property name="label">Invite</property>
+            <property name="tooltip-text" translatable="yes">Send invitation</property>
+          </object>
+          <packing>
+            <property name="pack-type">end</property>
+          </packing>
+        </child>
+        <child>
           <object class="GtkComboBox" id="combobox_cm">
             <property name="visible">True</property>
             <property name="popup-fixed-width">False</property>