add DisableEmailDomainAuthorization config option
Moved the defer syslogger.close to ensure that syslogger is defined
Merge pull request #5 from cloudfoundry/disable_email_domain_auth

add DisableEmailDomainAuthorization config option
Closing the dump channel and slight refactoring

Signed-off-by: Johannes Tuchscherer <jtuchscherer@pivotallabs.com>