Jewels: use 'Power' on M5/X5 to exit the plugin as in every other plugin. Mention...

Jewels: use 'Power' on M5/X5 to exit the plugin as in every other plugin. Mention this in the manual button table too and add the missing information for other targets as well. The table part in the tex file is restructured, a small workaround was necessary to make the Ipod manuals build correctly (is commented). Maybe someone with better tex skills could find a better solution?

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15151 a1c6a512-1295-4272-9138-f99709370657