History for cmgui programming style

changed:
-
Code structure

  * Files in graphics directory should include files in three_d_drawing 
		directory and not the other way round.  The platform specific parts
		of implementing OpenGL (GLX, WGL, AGL) are all only in three_d_drawing.

While many of these things are just convention and open to challenge, these are the common style points

  * Captial Initial.  type names generally have a their first character capitalised.  Historically all types were explicitly
    qualified with enum or struct every time they were used.  As more of the program migrates to C++ this style is being
    relaxed.  In particular in the API "id" types are being typedefed to include the struct.

  * Line formatting.  Generally everything flows on continuously.  I (Shane) tend to put spaces between parameters in a function
    call.  When a single line gets longer than about 80 characters we wrap it onto the next line and add one more level of
    indentation.

  * Comments.  In C we generally do not use the // C++ comment.  The IRIX compilers do not allow you too.  For commenting out a block
    we tend to use #if defined (OLD_CODE)  #endif /* defined (OLD_CODE) */

  * Preprocessor directives.  We tend to enclose the variable in brackets and include a comment at the end to show what is being closed.  
    I (Shane) have recently taken to indenting nested #ifs::

    #if defined (OLD_CODE)
    #  if defined (BOB)
    #  else /* defined (BOB) */
    #  endif /* defined (BOB) */
    #endif /* defined (OLD_CODE) */

  * Return codes.  Most functions return either an in or a pointer.  The int is normally 1 if the function was
    successful and 0 if not.  Pointer operations (normally CREATE/constructors) can return NULL on failure.
    It has been a long standing discussion if we need to change our error/exception handling to allow more levels and
    information and to enable the calling routines to catch errors.