This program will read from a file containing a scene described by the
Scene Description Language (SDL). It also uses a camera class to allow the user
to "fly-through" the 3-D scene that is created by the file. The SDL may also
include mesh files to display. It also is capable of generating a raytraced version
of the scene that is generated from the SDL file. The program was developed in a 
linux environment, and the makefile will only build the program for linux.

The executable can be run with a few different flags set:
'-b [num]' or '-B [num]'
    Set the block size for the ray tracer to the given number
'-w [num]' or '-W [num]'
    Set the width of the screen
'-h [num]' or '-H [num]'
    Set the height of the screen
'-f [filename]' or '-F [filename]'
    Set the file of the SDL scene you wish to display
    
The commands to fly-through the scene are as follows (They are all input from
the keyboard):
'w': Move forward down the -Z axis
's': Move backward down the +Z axis
'a': Move to the left down the -X axis
'd': Move to the right down the +X axis
'W': Move up the +Y axis
'S': Move down the -Y axis
'r': Rotate the scene clockwise around the Z axis
'R': Rotate the scene counter-clockwise around the Z axis
'y': Rotate the scene around Y axis at the current eye position clockwise
'Y': Rotate the scene around Y axis at the current eye position count-clockwise
'p': Rotate the scene around X axis at the current eye position downwards
'P': Rotate the scene around X axis at the current eye position up
't': Generate the ray traced scene