Rename screenshooter protocol to weston_screenshooter

Due to the effort of moving a way from non-prefixed protocols, rename
the weston specific screenshooter protocol to weston_screenshooter.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Mariusz Ceier <mceier+wayland@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/protocol/weston-screenshooter.xml b/protocol/weston-screenshooter.xml
new file mode 100644
index 0000000..8c4486c
--- /dev/null
+++ b/protocol/weston-screenshooter.xml
@@ -0,0 +1,12 @@
+<protocol name="weston_screenshooter">
+
+  <interface name="weston_screenshooter" version="1">
+    <request name="shoot">
+      <arg name="output" type="object" interface="wl_output"/>
+      <arg name="buffer" type="object" interface="wl_buffer"/>
+    </request>
+    <event name="done">
+    </event>
+  </interface>
+
+</protocol>