Fix single domain mishandling and Minor improvements
Fix for issue #58 (closed) and made some minor improvements:
Specifying single domain is handled correctly now.
Currently, when running each time, the ssl-domains.dat config file gets appended instead of regenerating. So had to manually delete it and re-run. So I added a line to remove the ssl-domains.dat file if exist and thus regenerate it each time.
Display the DNS records in table format for better readability.