Fix codegen not generating variable initialization code
Fix codegen not generating variable initialization code

codegen.py didn't generate code that would initialize the 'native' variable
of a generated native function if the function took no parameters.

This fixes issue #22.

WopsS/sampgdk,WopsS/sampgdk,Zeex/sampgdk,WopsS/sampgdk,Zeex/sampgdk,Zeex/sampgdk