Update ssh_key_transfer passwd; cinit zsh path.

Mod:
	shell_scripts/ssh_key_transfer.zsh
		-read in password once, then pass it to scp/ssh via sshpass instead of
		prompting the user to enter his/her password twice.

	install.zsh
		-merge directories dictionary into the special_files dictionary, seeing
		as directories don't require a different command sequence (as I
		initially assumed).