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/alarmclock.c

@@ -138,7 +138,13 @@ enum plugin_status plugin_start(const void* parameter)
     while(!quit) {
         button = get_button();
 
+#if (CONFIG_KEYPAD == IPOD_1G2G_PAD) \
+    || (CONFIG_KEYPAD == IPOD_3G_PAD) \
+    || (CONFIG_KEYPAD == IPOD_4G_PAD)
+        if (button == PLA_EXIT || button == PLA_CANCEL || button == PLA_UP)
+#else
         if (button == PLA_EXIT || button == PLA_CANCEL)
+#endif
             quit = true;
 
         FOR_NB_SCREENS(i) {