gnatsd currently uses a global logger. This can cause some problems
(especially around the config-reload work), but global variables are
also just an anti-pattern in general. The current behavior is
particularly surprising because the global logger is configured through
calls to the Server.
This addresses issue #500 by removing the global logger and making it a
field on Server.
Windows has limited support for signals, and does not define syscall.SIGUSR1. Log rotation will be handled differently in windows.
* Add signal.go for all non-windows builds
* Add signal_windows.go for windows builds.
Today, windows looks to be the only platform that does not have syscall.SIGUSR1 defined.
