[BuildTools] Why are ProjConfig.h files not `include once'?

[Lou Hafer]

Folks,

	Not exactly a BuildTools problem, but this list should reach the 
appropriate people.

	I was playing with the Osi unit test today and (to make a long story
short) tracked a bit of strangeness to the fact that the various ProjConfig.h
files do not guard against multiple inclusion.  To use Osi as an example,
there's the usual

#ifndef __OSICONFIG_H__
    ...
#endif

structure, but __OSICONFIG_H__ is never defined. I can't think of any good 
reason for the omission, but it seems universal. Every ProjConfig.h file I 
looked at has the same omission.

	Does anyone recall if there's a reason for this? I thought I'd better 
inquire before I change anything.
	
							Lou