Allow for all command types for roaming event

Prior to this commit roaming geofences only registered changes to
the SET command. Now it will work for SET/DEL/FSET, just like
non-roaming geofences.

To opt out of these events, explicitly choose which event you
would like to register when you create the geofences.

For example:

  NEARBY fleet FENCE COMMANDS set,del ROAM fleet * 5000

Will only fire off events from SET and DEL command.

Closes #597

internal/server/fence.go

@@ -99,9 +99,9 @@ func fenceMatch(
 				roamNearbys, roamFaraways =
 					fenceMatchRoam(sw.s, fence, details.id,
 						details.oldObj, details.obj)
-			}
-			if len(roamNearbys) == 0 && len(roamFaraways) == 0 {
-				return nil
+				if len(roamNearbys) == 0 && len(roamFaraways) == 0 {
+					return nil
+				}
 			}
 			detect = "roam"
 		} else {
@@ -235,6 +235,12 @@ func fenceMatch(
 	case "roam":
 		if len(msgs) > 0 {
 			var nmsgs []string
+			for _, msg := range msgs {
+				cmd := gjson.Get(msg, "command")
+				if cmd.Exists() && cmd.String() != "set" {
+					nmsgs = append(nmsgs, msg)
+				}
+			}
 			for i := range roamNearbys {
 				nmsg := extendRoamMessage(sw, fence,
 					"nearby", msgs[0], roamNearbys[i])