Added email sending support in tester script (refs #20133).

2.System/0_setup.py

4.Postfix/0_setup.py

5.Wowza/0_setup.py

6.Nginx/0_setup.py

default-conf.sh

envsetup.py

tester.py

tests/test_apt.sh

tests/test_nginx_conf_valid.sh

tests/test_ntp.sh

tests/test_postfix.py

tests/test_ubicast_packages_access.py

utils.py