XOM API for Processing XML with Java

[Dick Hollenbeck <dick AT machj.com>]

Please be careful of the cycle dependency checking code's 
overhead and how it might impact the speed of document 
building.  This checking is probably best done by using 
Assert()s so that it can be compiled in and out easily, as 
needed.

Speed is more important for most of us.  We'll find our bugs 
eventually.

Rusty, have you done a before and after benchmark?   This 
feature is not worth a speed hit to me.

Thanks for any consideration.