Add bbsync, ssh_key_transfer; update battery.

Add:
	Having worked with bash/zsh for the past two hours, I'm ready for a walk. A
	long, long walk.

	batteryWarningInit.zsh
		-fork batteryWarningd.zsh into the background when executing it, so that
		batteryWarningInit.zsh can exit after calling it and thus be removed
		from the process table.

	batteryWarningd.zsh
		-create battery_level_low and battery_level_high arrays containing
		lower- and upper-bound dangerous battery levels.
		-improve code modularity by creating a function to check the battery
		level against all arguments (as expanded from an array).
	bbsync.zsh
		-add script to sync music between my carbon and blackberry, with
		hand-rolled sync function because rsync wasn't suitable.

	ssh_key_transfer.zsh
		-add script to copy my public key into a remote machine's
		authorized_keys file.