Fixes #488. In rk_interval, use rk_random if the interval size is less than 2**32. For 64-bit machines, this means results will agree with 32-bit machines, and will be faster for these interval sizes (one less rk_random evaluation).
Fixes #488. In rk_interval, use rk_random if the interval size is less than 2**32.
For 64-bit machines, this means results will agree with 32-bit machines,
and will be faster for these interval sizes (one less rk_random evaluation).


git-svn-id: 77a43f9646713b91fea7788fad5dfbf67e151ece@3642 94b884b6-d6fd-0310-90d3-974f1d3f35e1

illume/numpy3k,jasonmccampbell/numpy-refactor-sprint,jasonmccampbell/numpy-refactor-sprint,Ademan/NumPy-GSoC,Ademan/NumPy-GSoC,teoliphant/numpy-refactor,efiring/numpy-work,illume/numpy3k,illume/numpy3k,illume/numpy3k,Ademan/NumPy-GSoC,chadnetzer/numpy-gaurdro,chadnetzer/numpy-gaurdro,teoliphant/numpy-refactor,efiring/numpy-work,teoliphant/numpy-refactor,teoliphant/numpy-refactor,efiring/numpy-work,chadnetzer/numpy-gaurdro,chadnetzer/numpy-gaurdro,jasonmccampbell/numpy-refactor-sprint,jasonmccampbell/numpy-refactor-sprint,teoliphant/numpy-refactor,Ademan/NumPy-GSoC,efiring/numpy-work