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Information on file: malloc4.c
Written by Xavier Bouyssounouse.
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Routines in this file dynamically allocate and free up
multi-dimensional arrays.  The main advantage of 
these routines over using fixed size arrays is that only
the amount of memory required is allocated, and then
freed when no longer needed.  Additionaly, the dimensions
of the arrays need not be passed as parameters to
functions since the dimensions are hidden in the memory
allocated.  Another advantage over fixed size arrays
is that the memory allocated by these mallocn routines 
is not necessarily contiguous, thus allowing the compiler
to grab available memory wherever it may find it.  On
the mac, for example, more than 32k cannot be allocated 
contiguously.  Thus, a fixed size array of 500X100 cannot
be allocated on the mac yet a variable size array with
these dimensions allocated by the mallocn routines in 
this file is permited.  A similar problem exists
on the suns.
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Information on malloc2(),malloc3(),malloc4().
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These routines dynamically allocate 2,3,4 dimensional 
arrays of unsigned char. For example, you can allocate an 
array of integers of size 5X6X7 as follows:
    int ***int_array;

    int_array= (int ***) malloc3(5,6,7*sizeof(int));
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Information on free2(),free3(),free4().
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These routines free up the memory dynamically allocated
by the mallocn routines.  For example, to free up the 
integer array allocated above, simply enter.
	free3((unsigned char **)int_array);
Note: free3(int_array) will generally work also.
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Information on getsize2(), getsize3(), getsize4().
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These routines determine the size of the input arrays.
For example, to determine the size of the integer array
allocated above, type:
    int ***int_image,num_imgs,num_rows,num_cols;

    ...
    getsize2(int_image,&num_imgs,&num_rows,&num_cols);  
    num_cols/= sizeof(int);
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