Convert Cocoa to default to OpenGL 3.2
Convert Cocoa to default to OpenGL 3.2

OSX is a bit more strict on its opengl so a bunch more changes were
required such as using in/out instead of attribute/varying. Also
handle gl_FragData properly for 3.2 as an output variable.

glew had a bug preventing glGenVertextAttribute... from being
defined. Made a change to correct that.

jmerkow/VTK,sumedhasingla/VTK,msmolens/VTK,SimVascular/VTK,sankhesh/VTK,demarle/VTK,mspark93/VTK,demarle/VTK,SimVascular/VTK,gram526/VTK,demarle/VTK,gram526/VTK,demarle/VTK,sumedhasingla/VTK,msmolens/VTK,msmolens/VTK,sankhesh/VTK,jmerkow/VTK,candy7393/VTK,sumedhasingla/VTK,jmerkow/VTK,demarle/VTK,sankhesh/VTK,sankhesh/VTK,sankhesh/VTK,sankhesh/VTK,sumedhasingla/VTK,jmerkow/VTK,msmolens/VTK,jmerkow/VTK,mspark93/VTK,demarle/VTK,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,msmolens/VTK,gram526/VTK,keithroe/vtkoptix,sumedhasingla/VTK,mspark93/VTK,msmolens/VTK,keithroe/vtkoptix,sumedhasingla/VTK,candy7393/VTK,SimVascular/VTK,keithroe/vtkoptix,msmolens/VTK,msmolens/VTK,jmerkow/VTK,gram526/VTK,gram526/VTK,gram526/VTK,SimVascular/VTK,sankhesh/VTK,candy7393/VTK,gram526/VTK,sumedhasingla/VTK,SimVascular/VTK,candy7393/VTK,candy7393/VTK,keithroe/vtkoptix,demarle/VTK,sankhesh/VTK,keithroe/vtkoptix,jmerkow/VTK,candy7393/VTK,candy7393/VTK,sumedhasingla/VTK,SimVascular/VTK,mspark93/VTK,gram526/VTK,mspark93/VTK,mspark93/VTK,mspark93/VTK,mspark93/VTK,candy7393/VTK,SimVascular/VTK,demarle/VTK,keithroe/vtkoptix,jmerkow/VTK