fix android resize and lingering glew issue

Change-Id: Ie8f280ef40406de3f58115bfbe11dfa7fc3ceceb
Merge topic 'handle-android-resize' into master

410cbc51 fix android resize and lingering glew issue
vtkglew: Install glew header files

These are needed to use the module from applications built against
the VTK install tree.

Change-Id: I729d56634eace053d3c2a5e79d69a44655aeccdb
BUG: Fixed opacity mapping when scalar array is vtkUnsignedChar.

Incorrect logic in vtkDiscretizableColorTransferFunction::MapScalars()
ended up interpretting the presence of vtkUnsignedCharArray for scalar
as meaning that the transfer function is not mapping scalars to colors
but directly rendering them. This lead
vtkDiscretizableColorTransferFunction is not do opacity mapping even
when requested by user. Fixed the check and added some documentation for
that check to better explain its purpose.

Change-Id: Ic8f4c0188194a363a8640befe1bd4090acc5c0ff
Merge topic 'fix_opacity_mapping' into master

a5daf047 BUG: Fixed opacity mapping when scalar array is vtkUnsignedChar.
Merge topic 'install-vtkglew-headers' into master

4998c13b vtkglew: Install glew header files