Handle 'dot' in ACL from ls when SELinux is enabled

'ls' uses the last character to indicate if an alternate access
method applies to a file in the permission string.

'.' indicates SELinux is used as an access method.  TestFileHelper
did not account for this case.

'+' indicates any other alternate access method is used. This was
already checked.
Merge pull request #199 from big-guy/selinux-support

Handle 'dot' in ACL from ls when SELinux is enabled