shell-animation: add conf option in shell

Now we can choose zoom or fade in weston.ini
to fulfill and customize the user experence easier.

Signed-off-by: Juan Zhao <juan.j.zhao@intel.com>
diff --git a/weston.ini b/weston.ini
index 31d2e51..7693253 100644
--- a/weston.ini
+++ b/weston.ini
@@ -4,11 +4,13 @@
 background-color=0xff002244
 panel-color=0x90ff0000
 locking=true
+animation=zoom
 
 #type=tablet-shell.so
 #lockscreen-icon=/usr/share/icons/gnome/256x256/actions/lock.png
 #lockscreen=/usr/share/backgrounds/gnome/Garden.jpg
 #homescreen=/usr/share/backgrounds/gnome/Blinds.jpg
+#animation=fade
 [launcher]
 icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png
 path=/usr/bin/gnome-terminal