feat: SpaceAPI v15 support

Delete types/v14.go, replace with v15.go.

Rename internal types to not include message version.
I don't currently see the need to support multiple message
versions that have incompatible layouts.
v15 is backwards compatible with v14, so the config example now
specifies both.

Rename the "response" field in the config file to "static" as
dynamic/static makes more sense from the user's perspective.
(Internally it's still SpaceapidConfig.{Dynamic,Response}
to align with type names and usage.)

persistence/persistentState.go

@@ -16,11 +16,11 @@ const (
 
 // MergeOldState merges a given SpaceAPIResponse with the state saved at the time of last program exit and then deletes
 // the file containing the old state.
-func MergeOldState(response *types.SpaceAPIResponseV14) {
+func MergeOldState(response *types.SpaceAPIResponse) {
 	var (
 		err            error
 		oldState       []byte
-		persistedState types.PersistentStateV14
+		persistedState types.PersistentSpaceState
 	)
 
 	log.Println("Merging old state from", persistentStatePath, "...")
@@ -48,7 +48,7 @@ func MergeOldState(response *types.SpaceAPIResponseV14) {
 	}
 
 	// Merge state
-	response.State = persistedState.State
+	response.State.FromPersistentSpaceState(persistedState)
 
 	// Merge sensors
 	for key, environmentSensors := range persistedState.Sensors {
@@ -72,7 +72,7 @@ removeOld:
 	}
 }
 
-func SaveCurrentState(response types.SpaceAPIResponseV14) {
+func SaveCurrentState(response types.SpaceAPIResponse) {
 	// Create state directory if not present
 	err := os.MkdirAll(persistentStateDir, 0750)
 	if err != nil {
@@ -87,7 +87,7 @@ func SaveCurrentState(response types.SpaceAPIResponseV14) {
 	defer file.Close()
 
 	// Create persistent state
-	persistentStateV14 := types.PersistentStateV14{
+	persistentStateV14 := types.PersistentSpaceState{
 		State: struct {
 			Open       bool   `json:"open"`
 			LastChange int64  `json:"lastchange"`