Fixes and enhancements.

Fixes:

- TLS flag should be passed as 0 or 1, and not undef to prevent a warning
- The Net::XMPP::Client often sets an error code itself during connection failure, so display if possible

Enhancements:

- Enable SRV lookups (make passing hostname optionsal)
- Allow higher debug level to be specified on cmd line using -d <n> or -d -d -d -d  
- Add option "--sso" which sets user (user@domain) from current OS, allows empty password