Add support for syslog formatting and TLS

With this commit seelog can be used to log to syslog, optionally over TLS (e.g. to rsyslog) so logs can be transmitted directly to a central log server.
Revert support for syslog formatting

This partially reverts commit 4832436a1906926858427530a34954f0f789993b.
Merge pull request #50 from tpjg/syslog

Add support for syslog formatting and TLS