thrift-py: make fastbinary C90 compiler friendly
thrift-py: make fastbinary C90 compiler friendly

Summary:
setuptools-based distributions use the C compiler, while
internally, we build with the a C++ compiler.  This diff makes
fastbinary.c more C-compiler friendly for open source.

Test Plan:
verified fastbinary.c successfully compiles internally as well
as externally with python 2.6. 2.7, 3.3, and 3.4.

Reviewed By: haijunz@fb.com

Subscribers: doug, ruibalp, alandau, bmatheny

FB internal diff: D1420644

jesboat/fbthrift,uber/fbthrift,uber/fbthrift,kangkot/fbthrift,jesboat/fbthrift,jesboat/fbthrift,maxwell-demon/fbthrift,sinjar666/fbthrift,maxwell-demon/fbthrift,HankFaan/fbthrift,HankFaan/fbthrift,jesboat/fbthrift,getyourguide/fbthrift,LinusU/fbthrift,guker/fbthrift,Orvid/fbthrift,raphaelamorim/fbthrift,LinusU/fbthrift,maxwell-demon/fbthrift,LinusU/fbthrift,project-zerus/fbthrift,kangkot/fbthrift,fengshao0907/fbthrift,soumith/fbthrift,fengshao0907/fbthrift,jesboat/fbthrift,facebook/fbthrift,Orvid/fbthrift,kangkot/fbthrift,guker/fbthrift,project-zerus/fbthrift,Orvid/fbthrift,uber/fbthrift,sinjar666/fbthrift,LinusU/fbthrift,SergeyMakarenko/fbthrift,sinjar666/fbthrift,chjp2046/fbthrift,SergeyMakarenko/fbthrift,raphaelamorim/fbthrift,fengshao0907/fbthrift,SergeyMakarenko/fbthrift,SergeyMakarenko/fbthrift,maxwell-demon/fbthrift,Orvid/fbthrift,project-zerus/fbthrift,getyourguide/fbthrift,raphaelamorim/fbthrift,soumith/fbthrift,getyourguide/fbthrift,facebook/fbthrift,sinjar666/fbthrift,project-zerus/fbthrift,jesboat/fbthrift,chjp2046/fbthrift,sinjar666/fbthrift,getyourguide/fbthrift,project-zerus/fbthrift,sinjar666/fbthrift,raphaelamorim/fbthrift,soumith/fbthrift,getyourguide/fbthrift,getyourguide/fbthrift,soumith/fbthrift,soumith/fbthrift,fengshao0907/fbthrift,project-zerus/fbthrift,fengshao0907/fbthrift,kangkot/fbthrift,project-zerus/fbthrift,chjp2046/fbthrift,soumith/fbthrift,Orvid/fbthrift,chjp2046/fbthrift,Orvid/fbthrift,kangkot/fbthrift,maxwell-demon/fbthrift,getyourguide/fbthrift,guker/fbthrift,chjp2046/fbthrift,fengshao0907/fbthrift,maxwell-demon/fbthrift,LinusU/fbthrift,sinjar666/fbthrift,guker/fbthrift,chjp2046/fbthrift,SergeyMakarenko/fbthrift,project-zerus/fbthrift,fengshao0907/fbthrift,guker/fbthrift,guker/fbthrift,jesboat/fbthrift,uber/fbthrift,jesboat/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,kangkot/fbthrift,getyourguide/fbthrift,chjp2046/fbthrift,uber/fbthrift,facebook/fbthrift,SergeyMakarenko/fbthrift,maxwell-demon/fbthrift,fengshao0907/fbthrift,LinusU/fbthrift,LinusU/fbthrift,project-zerus/fbthrift,sinjar666/fbthrift,jesboat/fbthrift,kangkot/fbthrift,facebook/fbthrift,HankFaan/fbthrift,SergeyMakarenko/fbthrift,kangkot/fbthrift,SergeyMakarenko/fbthrift,LinusU/fbthrift,fengshao0907/fbthrift,uber/fbthrift,HankFaan/fbthrift,kangkot/fbthrift,maxwell-demon/fbthrift,soumith/fbthrift,soumith/fbthrift,fengshao0907/fbthrift,Orvid/fbthrift,Orvid/fbthrift,fengshao0907/fbthrift,chjp2046/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,HankFaan/fbthrift,soumith/fbthrift,project-zerus/fbthrift,facebook/fbthrift,sinjar666/fbthrift,chjp2046/fbthrift,uber/fbthrift,guker/fbthrift,sinjar666/fbthrift,uber/fbthrift,sinjar666/fbthrift,raphaelamorim/fbthrift,project-zerus/fbthrift,LinusU/fbthrift,getyourguide/fbthrift,soumith/fbthrift,guker/fbthrift,Orvid/fbthrift,HankFaan/fbthrift,HankFaan/fbthrift,uber/fbthrift,maxwell-demon/fbthrift,SergeyMakarenko/fbthrift,Orvid/fbthrift,kangkot/fbthrift,maxwell-demon/fbthrift,guker/fbthrift,raphaelamorim/fbthrift,uber/fbthrift,guker/fbthrift,LinusU/fbthrift,guker/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,jesboat/fbthrift,chjp2046/fbthrift,chjp2046/fbthrift,HankFaan/fbthrift,uber/fbthrift,kangkot/fbthrift,soumith/fbthrift,jesboat/fbthrift,HankFaan/fbthrift,Orvid/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,HankFaan/fbthrift,uber/fbthrift,maxwell-demon/fbthrift,jesboat/fbthrift,facebook/fbthrift,chjp2046/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,HankFaan/fbthrift,raphaelamorim/fbthrift,raphaelamorim/fbthrift,project-zerus/fbthrift,getyourguide/fbthrift,LinusU/fbthrift,SergeyMakarenko/fbthrift