definition of struct rb_ndoe on the endianess is the only explanation I have
why nobody complained about this on i386 - I don't understand why it makes a
difference for gcc though)
has a significant code size savings over <sys/tree.h>.
Also change prop_number_t to store all number objects in an r-b tree,
only ever allocating one object for any given number (we can do this
because numbers are immutable). This results in significant run-time
memory savings.