Improved receive.go

- Fixed configuration listen-port semantics
- Improved receive.go code for updating listen port
- Updated under load detection, how follows the kernel space implementation
- Fixed trie bug accidentally introduced in last commit
- Added interface name to log (format still subject to change)
- Can now configure the logging level using the LOG_LEVEL variable
- Begin porting netsh.sh tests
- A number of smaller changes

src/uapi_linux.go

@@ -44,7 +44,12 @@ func (l *UAPIListener) Accept() (net.Conn, error) {
 }
 
 func (l *UAPIListener) Close() error {
-	return l.listener.Close()
+	err1 := unix.Close(l.inotifyFd)
+	err2 := l.listener.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
 }
 
 func (l *UAPIListener) Addr() net.Addr {