Purge live-boot in uninstall function of 13.10 script

My script modifies scripts in /lib/live/boot/ while it runs. These scripts are part of live-boot.
If these modifications are not undone when the script runs again (if RAM_booster was uninstalled
and installed again), they will be applied twice, giving unpredictable results on boot.
Merge branch 'purge_live-boot_on_uninstall'