zshrc: run tlog alias with --follow=name

It's annoying to follow the syslog, but then tools like logroate kicking
in to rename syslog to syslog.1. Then you're stuck with the "old" syslog
file content, by using the --follow=name option we can fix this.

Quoting from tail(1):

| With --follow (-f), tail defaults to following the file descriptor,
| which means that even if a tail'ed file is renamed, tail will continue
| to track its end. This default behavior is not desirable when you really
| want to track the actual name of the file, not the file descriptor
| (e.g., log rotation). Use --follow=name in that case. That causes tail
| to track the named file in a way that accommodates renaming, removal and
| creation.