Fix for: Compilation failure due to missing OpenGL utility file includes

Hi,

when I tried to compile libmv I ran into 3 compilation errors. Everytime a GLU function was not declared.

As an example:
libmv/src/ui/tvr/main_window.cc:252:61: error: 'gluBuild2DMipmaps' was not declared in this scope

The problems only occur with files under the libmv/src/ui/tvr/ directory.

This pull request fixes these problems by including GL/glu.h at the correct spots.

Cheers,
Konrad