Require version 2 of phosh's private interface

TODO: add the protocol to this commit

protocol/phosh-private.xml

@@ -23,29 +23,29 @@
     </request>
   </interface>
 
-  <!-- window switch handling -->
-  <interface name="phosh_private_app_switcher" version="1">
-
+  <!-- application switch handling -->
+  <!-- TODO: apps with multiple windows -->
+  <interface name="phosh_private_app_switcher" version="2">
     <enum name="error">
       <entry name="invalid_argument" value="0"
              summary="an invalid argument was provided in a request"/>
     </enum>
 
-    <request name="list_apps" since="1">
-      <description summary="Get current views"/>
+    <request name="list_apps" since="2">
+      <description summary="Get currently running applications"/>
     </request>
 
-    <request name="raise_app" since="1">
-      <description summary="raise the give view"/>
+    <request name="raise_app" since="2">
+      <description summary="raise the surface of the given application to the top"/>
       <arg name="app_id" type="string" summary="The app_id of the view"/>
     </request>
 
-    <event name="app" since="1">
-      <description summary="advertise available app"/>
-      <arg name="app_id" type="string" summary="the app_id of a view"/>
+    <event name="app" since="2">
+      <description summary="report a running application"/>
+      <arg name="app_id" type="string" summary="the app_id of the application"/>
     </event>
 
-    <event name="list_apps_done" since="1">
+    <event name="list_apps_done" since="2">
       <description summary="all apps were sent"/>
     </event>
   </interface>

src/phosh-wayland.c

@@ -59,7 +59,7 @@ registry_handle_global (void *data,
         registry,
         name,
         &phosh_private_interface,
-        1);
+        2);
   } else  if (!strcmp (interface, zwlr_layer_shell_v1_interface.name)) {
       priv->layer_shell = wl_registry_bind (
         registry,