Adds GLU library to GCC linker library list

- GLU library added to Eclipse linker library list.
Adds gl and glu header files to includes

- The gl and glu libraries are added to the list of includes.
Changes UI initialisation function

- UI initialisation function has been modified to disable depth
testing, cull facing and not activate blending.
Adds destroy window call on exit

- Main window is destroyed before exit command issued.
Fixes tree draw child function tree matrix index

- The tree matrix wasn’t indexed correctly. This has now been corrected.
Changes DrawSquareNode function graphics handling

- Handling of graphics by the DrawSquareNode function has been
modified. This includes the removal of window setting, clearing of
buffers.
- Push matrix and pop matrix added.
Changes DrawLinesNode function graphics handling

- Introduces push matrix and pop matrix.
- Removes need to define window and clearing of graphics buffers.
- Change is almost identical to
716b3b10e112fe72962f90d7c7b2741a178a354e.
Changes DrawTree window setting

- Window is no longer defined when calling the DrawTree function. This
allows the parent function to define which space and only one call is
issued.
Adds movement detection to main window renderer

- Main window renderer detects movement and updates.
Adds viewport setting define to reshape function

- Probably unnecessary but the reshape function now defines the
viewport and sets a few graphics options too.
Changes spacing of tree nodes and connections

- The tree nodes (squares) and their connections (lines) have new
spacing. It’s not perfect but it’s functional for now.
Changes GLUT initialisation function

- GLUT initialisation function has been modified to remove the idle
function call and viewport settings.
Adds glutMainLoop call to the main function

- Main function initialises GLUT and calls glutMainLoop.
Changes tree sub window rendering

- Rendering of the tree sub window has been changed. View perspective
is now set and the camera is set via gluLookAt.
- Introduces push and pop matrix calls and matrix mode changes.