Fix deltas referring to last system saved

If a system is added, it is added to treema at the end of the list of systems. Treema then raises it's changed event resulting in this order being set on the level. The next time a system is added, the first system is in it's correct position and so the delta shows it as moving. This changes ensures we save the correct order in the first instance.

app/views/editor/level/systems_tab_view.coffee

@@ -59,12 +59,7 @@ module.exports = class SystemsTabView extends View
     unless systems.length
       systems = @buildDefaultSystems()
       insertedDefaults = true
-
-    systemModels = @supermodel.getModels LevelSystem
-    systemModelMap = {}
-    systemModelMap[sys.get('original')] = sys.get('name') for sys in systemModels
-    systems = _.sortBy systems, (sys) -> systemModelMap[sys.original]
-
+    systems = @getSortedByName systems
     treemaOptions =
       # TODO: somehow get rid of the + button, or repurpose it to open the LevelSystemAddView instead
       supermodel: @supermodel
@@ -84,7 +79,14 @@ module.exports = class SystemsTabView extends View
     @onSystemsChanged() if insertedDefaults
 
   onSystemsChanged: (e) =>
-    @level.set 'systems', @systemsTreema.data
+    systems = @getSortedByName @systemsTreema.data
+    @level.set 'systems', systems
+
+  getSortedByName: (systems) =>
+    systemModels = @supermodel.getModels LevelSystem
+    systemModelMap = {}
+    systemModelMap[sys.get('original')] = sys.get('name') for sys in systemModels
+    _.sortBy systems, (sys) -> systemModelMap[sys.original]
 
   onSystemSelected: (e, selected) =>
     selected = if selected.length > 1 then selected[0].getLastSelectedTreema() else selected[0]