clean up code

	simplify messages with echo "changing directory to $_"
	move read -p commands inside else statements to reduce user input friction

On branch centos7
Changes to be committed:

	modified:   scripts/firewalld.sh
	modified:   scripts/lemp.sh
	modified:   scripts/middleman.sh
	modified:   scripts/nginx_config.sh
	modified:   scripts/wordpress_install.sh
	modified:   scripts/workstation_ssh.sh
	modified:   setup.sh
refactoring

	simplify program installs to use loops of program lists
	add check if program is already installed
	add global variables for program lists

On branch centos7
Changes to be committed:

	modified:   scripts/lemp.sh
	modified:   scripts/linux_update.sh
	modified:   scripts/middleman.sh
	modified:   setup.sh