plugins: Improve usability of iPod keymaps

- Reduce need to press multiple buttons at
the same time to quit a plugin

- Have "Menu" be default way to quit plugins or
to access plugin menu

- Fall back to (Long) "Select" or Long "Menu"
in cases where Menu button isn't available
(e.g. in ImageViewer and many games)

out of scope:
boomshine, lua_scripts, Rockpaint,
Doom, Duke3D, Pacbox, Quake,
Sgt-Puzzles, Wolf3D, XWorld,
Minesweeper, Pixel Painter, Spacerocks

Change-Id: I6d4dc7174695fe4b8ee9cbaccb21bdbfe6af5c48

apps/plugins/fire.c

@@ -56,10 +56,17 @@ const struct button_mapping* plugin_contexts[]= {
 };
 
 #define FIRE_QUIT                   PLA_CANCEL
-#define FIRE_QUIT2                  PLA_EXIT
 #define FIRE_SWITCH_FLAMES_TYPE     PLA_LEFT
 #define FIRE_SWITCH_FLAMES_MOVING   PLA_RIGHT
 
+#if (CONFIG_KEYPAD == IPOD_1G2G_PAD) \
+    || (CONFIG_KEYPAD == IPOD_3G_PAD) \
+    || (CONFIG_KEYPAD == IPOD_4G_PAD)
+#define FIRE_QUIT2                  PLA_UP
+#else
+#define FIRE_QUIT2                  PLA_EXIT
+#endif
+
 #ifdef HAVE_SCROLLWHEEL
 #define FIRE_INCREASE_MULT          PLA_SCROLL_FWD
 #define FIRE_INCREASE_MULT_REP      PLA_SCROLL_FWD_REPEAT