Many other cmake improvements.

Fix GLEW/GLU dependency mess.

Set build configuration variables and pass down to to superbuild
external projects.

1. Removing GLEW external project. Glew is now
built with vtk, in order to use it just include
the vtk use file and add the vtkglew library
to the target link directive.

2. BUILD_SHARED_LIBS is now forced to be OFF for
Windows MSVC builds.

Build external shared libs in order to avoid linking issues in windows.