deleteSelection when an output node had multiple connections only the first one was deleted, needed a new function to return a vector of connections that are now looped and deleted at the end of delete selection.
few other minor additions and fixes.
Adds the ground work for geometry shaders
Expands shaderData and gfxShader to allow for more shader types
note: when building a GFXShader in source you have to call setShaderStageFile with the shaderStage and the filepath for that stage.
Once we add compute shaders this will become more apparent as compute shaders are a stage of their own and do not require vertex and pixel files whereas other shaders sometimes do.
