Add option to log service/task output to the console

Example:
    service log:console [2] /usr/sbin/udhcpd -f -- DHCP Server

Signed-off-by: Robert Andersson <robert.m.andersson@se.atlascopco.com>

src/svc.h

@@ -119,6 +119,7 @@ typedef struct svc {
 	struct {
 		char   enabled;
 		char   null;
+		char   console;
 		char   file[64];
 		char   prio[20];
 		char   ident[20];