added lildebi shutdown on ACTION_EJECT and ACTION_MEDIA_BUTTON

added new MediaEjectReceiver.java for that

closes #113 https://github.com/guardianproject/lildebi/issues/113
removed unused import
'no_sdcard_message' msg is not required
when installing under internal storage
remove terminal initial command if Lil'debi is not running
Mark Install on Internal Storage feature as Beta
add MEDIA_SHARED for MediaEjectReceiver
fix intent action names in AndroidManifest.xml

closes #113 https://github.com/guardianproject/lildebi/issues/113
RECEIVE_BOOT_COMPLETED permission is needed in order to receive the broadcast BOOT_COMPLETED