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

manual/plugins/jewels.tex

@@ -46,8 +46,8 @@ skillfully swapping pairs of jewels.
       ,IAUDIO_X5_PAD,COWON_D2_PAD,SANSA_FUZEPLUS_PAD}{\ButtonPower}
     \opt{SANSA_FUZE_PAD}{Long \ButtonHome}
     \opt{GIGABEAT_S_PAD}{\ButtonBack}
-    \opt{IPOD_3G_PAD,MPIO_HD300_PAD}{\ButtonMenu}
-    \opt{IPOD_4G_PAD}{\ButtonSelect+ \ButtonMenu}
+    \opt{MPIO_HD300_PAD}{\ButtonMenu}
+    \opt{IPOD_4G_PAD,IPOD_3G_PAD}{Long \ButtonSelect}
     \opt{IRIVER_H100_PAD,IRIVER_H300_PAD}{\ButtonOff}
     \opt{PBELL_VIBE500_PAD}{\ButtonRec}
     \opt{SAMSUNG_YH92X_PAD,SAMSUNG_YH820_PAD}{\ButtonRew}