Refactor type generator

* Allows for generating top-level types for any embedded struct so
  that sub-types can be properly instantiated from calling code
  * Specifying `-no-embedded-types` will generate top-level types
    rather than embedding the struct

* Refactored "Device" API
  * All fields set to `omitempty` because it describes all possible
    device types, so effectively any field could be omitted any time
  * Fixed `get` call for "Device" API; replacing `rest` with `stat`

* Generated `get` and `update` calls for `Setting*` APIs

* Added `5.14.23` JSON files

fields/5.14.23/ScheduleTask.json

@@ -0,0 +1,14 @@
+{
+    "cron_expr": "",
+    "action": "stream|upgrade",
+    "execute_only_once": "true|false",
+    "name": "",
+    "broadcastgroup_id": "",
+    "stream_type": "media|sample",
+    "upgrade_targets": [{
+        "mac":"^([0-9A-Fa-f]{2}:){5}([0-9A-Fa-f]{2})$"
+    }],
+    "mediafile_id": "",
+    "sample_filename": "",
+    "additional_sounds_enabled": "true|false"
+}