Don't build extension module when there are no sources. This allows generating arbitrary .py files within Extension.
Don't build extension module when there are no sources. This allows generating arbitrary .py files within Extension.


git-svn-id: 77a43f9646713b91fea7788fad5dfbf67e151ece@780 94b884b6-d6fd-0310-90d3-974f1d3f35e1

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