Simplify scalar arithmetic and improve it in cases of array scalars mixed with masked arrays.
Simplify scalar arithmetic and improve it in cases of array scalars mixed with masked arrays.

git-svn-id: 77a43f9646713b91fea7788fad5dfbf67e151ece@2213 94b884b6-d6fd-0310-90d3-974f1d3f35e1

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