ivi-shell: developer mode debug key bindings

Add a weston.ini option for ivi-shell to enable "developer mode".

When developer mode is enabled, hook up the debug key bindings.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Acked-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Reviewed-by: Daniel Stone <daniels@collabora.com>
diff --git a/ivi-shell/weston.ini.in b/ivi-shell/weston.ini.in
index 8aa5746..e05e8da 100644
--- a/ivi-shell/weston.ini.in
+++ b/ivi-shell/weston.ini.in
@@ -5,6 +5,8 @@
 ivi-module=hmi-controller.so
 ivi-shell-user-interface=@abs_top_builddir@/weston-ivi-shell-user-interface
 
+#developermode=true
+
 cursor-theme=default
 cursor-size=32