These have been introduced in Leopard and default to int and unsigned int.
In 64-bit Snow Leopard they are long and unsigned long. This caused issues
with the getRectsBeingDrawn message which needs a pointer to a NSInteger
(long on 64-bit!) but we passed in an integer. Surprisingly this problem
was visible when compiling with -O0 (segfault), but *not* when compiling
with -O1. Other messages were NSInteger is now needed have also been
adapted.
Since NSInteger and NSUInteger are not available on Tiger, a define
has been added to add typedefs for these when they have not been defined
by the system headers.