Graphics.SceneManager:  Added OnError event
Removed OBJ support
Fix error preventing the driver icon from being loaded occasionally

Fixes #17
Graphics.Asset: Added LinkType enum to allow more selective application of the linked item transformation matrix
Removed ContentPipeline\Core\OBJImporter.cs
Graphics.Model:  MoveBone now correctly relocates child bones too

Fixes #21
Fix incorrectly rounding away negative numbers
New icons.  Thanks FatCat!
Making use of the new icons
Rather that rebuilding the treeview every time we'll simply apply the given change

Resolves #20
ContentPipeline.Stainless.MDLImporter:  Correctly imports all vertex information

Fixes #19
Preferences: Added path to Carmageddon/Splat Pack
Graphics.Primitives:  Added Sphere class
Draw a sphere if the node has no mesh data

Resolves #15
Added handling for VFX nodes
Rough and ready support for importing C1 assets
Changes to camera and key handling in advance of mouse support
ContentPipeline.Core.FBXImporter:  Fixes most import problems
ContentPipeline.Core.FBXExporter:  Not sure what this fixes
ContentPipeline.Stainless.CNTExporter:  Removed scale fiddling in CNT export