Fixed firewalld package issue

Firewalld package cannot be uninstalled, because other packages might be dependent
on it. This patch makes just firewalld service to stop and be disabled.

For more info please check: https://bugzilla.redhat.com/show_bug.cgi?id=1148399
ip6tables isn't supported on EL5

No need to test ip6tables purging on EL5 since the ip6tables provider
isn't supported.
Merge pull request #428 from mhaskel/el5_test_fix

ip6tables isn't supported on EL5
Merge pull request #426 from paramite/firewalld-fix

Fixed firewalld package issue