skin rework (FS#10922) notable changes:

- simplify the setting/skin relationship. settings are used as the fallback if it's not specified in the skin
- backdrop buffers are now in the skin buffer (which has also increased slightly to accomodate 1 backdrop for each skin and 2 full colour screens for bmps (up for 1.5))
- if no %X is specified in a skin then the backdrop setting will be used. use %Xd to explicitly disable a skin from displaying a backdrop
- the base skin can now specify a backdrop.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24366 a1c6a512-1295-4272-9138-f99709370657

apps/screen_access.c

@@ -201,9 +201,7 @@ struct screen screens[NB_SCREENS] =
         .backlight_set_timeout=&backlight_set_timeout,
 #if LCD_DEPTH > 1
         .backdrop_load=&backdrop_load,
-        .backdrop_unload=&backdrop_unload,
         .backdrop_show=&backdrop_show,
-        .backdrop_hide=&backdrop_hide,
 #endif
 #ifdef HAVE_BUTTONBAR
         .has_buttonbar=false,
@@ -291,9 +289,7 @@ struct screen screens[NB_SCREENS] =
         
 #if LCD_DEPTH > 1
         .backdrop_load=&remote_backdrop_load,
-        .backdrop_unload=&remote_backdrop_unload,
         .backdrop_show=&remote_backdrop_show,
-        .backdrop_hide=&remote_backdrop_hide,
 #endif
 #ifdef HAVE_BUTTONBAR
         .has_buttonbar=false,