Ability to edit YTYP files and MLO Entity Defintions + Revisions to grass brush (#33)

* - Add ability to edit/add ytyp files to project.
- Add ability to edit/add ytyp archetype files to ytyp.
- Add ability to add/remove entities from mlo archetype defs.
- Add ability to save ytyp files.
- Add dialog popup before optimizing grass batches.
- Fix grass batches not being selected when chaning selection in project explorer.
- Merged with upstream/master.
- Squashed last 4 commits for PR cleanliness.

* Fixed windows forms reference error.

* - Added error checking to deleting mlo entities.
- Fixed various bugs with deleting mlo entities.
- Fixed edit archetype panel Asset Type box.
- Removed redundant/unnecessary.
- Removed backwards references between MCEntityDef and YmapEntityDef. All ymap entity to mcentity references are grabbed using indecies in the MloInstanceData class.
- Fixed "YmapMenu" not showing when selecting entities/mlo entities in project form.

Current bugs:
- Loading a ytyp file -- mlo entities are not editiable, and are created in the world.
- entitysets are not editable (properly).
- Removing an mloinstancedef from a ymap does not delete the mlo instance's gizmo from the world, and it's still selectable. (Although all references are lost, and I believe collected by the GC?)

* - Moved archetype initialization methods YmapFile.InitYmapEntityArchetypes(GameFileCache gfc)  and MloInstanceData.InitYmapEntityArchetypes(GameFileCache gfc)
- Added ability to load mlo instance defs through ymap files.
- Fixed add method for mlo archetypes.

* - Removed SetOrientationInv.
- Removed unreachable code + updated comment.
- Renamed CreateEntity to CreateYmapEntity, and renamed params for consistency.

* Split calls to CreateYmapEntity() and MloArchetype.AddEntity().

* Fixed redundant rotation inversions.

* - Added ability to select rooms.
- Changed tree view grouping for mlo entities.
- Fixed projectexplorer selection bugs.
- Added ability to toggle mlo entity sets.
- Fixed some change events when editing archetypes.

Project/ProjectFile.cs

@@ -59,10 +59,11 @@ namespace CodeWalker.Project
                 Xml.AddChildWithInnerText(doc, ytypselem, "Item", ytypfilename);
             }
 
+
             var yndselem = Xml.AddChild(doc, projelem, "YndFilenames");
             foreach (string yndfilename in YndFilenames)
             {
-                Xml.AddChildWithInnerText(doc, yndselem, "Item", yndfilename);
+                Xml.AddChildWithInnerText(doc, ytypselem, "Item", yndfilename);
             }
 
             var ynvselem = Xml.AddChild(doc, projelem, "YnvFilenames");