Add index property to viewpoint

Author: GeorgDangl

README.md

@@ -1151,6 +1151,7 @@ JSON encoded body using the "application/json" content type.
 |parameter|type|description|required|
 |---------|----|-----------|--------|
 | x, y, z | number | numbers defining either a point or a vector | optional |
+| index | number | parameter for sorting | optional |
 | orthogonal camera | object | orthogonal camera view | optional |
 | camera_view_point | object | viewpoint of the camera | optional |
 | camera_directiont | object | direction of the camera | optional |

Schemas_draft-03/Collaboration/Viewpoint/viewpoint_GET.json

@@ -2,6 +2,12 @@
     "title": "viewpoint_GET",
     "type": "object",
     "properties": {
+		"index": {
+		    "type": [
+			    "number",
+				"null"
+			]
+		},
         "guid": {
             "required": true,
             "type": "string"

Schemas_draft-03/Collaboration/Viewpoint/viewpoint_POST.json

@@ -2,6 +2,12 @@
     "title": "viewpoint_POST",
     "type": "object",
     "properties": {
+		"index": {
+		    "type": [
+			    "number",
+				"null"
+			]
+		},
         "orthogonal_camera": {
             "type": ["object",
             "null"],

Schemas_draft-03/Collaboration/Viewpoint/viewpoint_PUT.json

@@ -2,6 +2,12 @@
     "title": "viewpoint_PUT",
     "type": "object",
     "properties": {
+	    "index": {
+		    "type": [
+			    "number",
+				"null"
+			]
+		},
         "orthogonal_camera": {
             "type": ["object",
             "null"],