Fixed shader texture prop sheet, added scene label prop sheet
Adding sprite in scene editor, sprite sheet prop, added ability to set sprite size explicitly
Added icon for empty entities in scene editor, fixed non retina icons in scene editor, added ability to add empty entity in scene editor
Adding sounds in scene editor, hooked up sound prop sheet
Added ability to add cameras in the scene editor, added camera property sheet, camera icons
Removed Polygon from Polycode, meshes now contain vertices directly
Added indexed mesh support to Polycode, added indexed mesh support to .mesh format, polyimport will now always generate an indexed mesh file, rewrote .mesh format to support flags for different vertex attributes, updated polyimport with options to only include chosen vertex attributes, changed 3d asset import UI to reflect new polyimport changes, added support for secondary UV coordinates