Fix boost.python string conversion.
Fix boost.python string conversion.

hoodie/libavg,th3infinity/libavg,libavg/libavg,libavg/libavg,libavg/libavg,libavg/libavg,hoodie/libavg,hoodie/libavg,th3infinity/libavg,th3infinity/libavg,th3infinity/libavg,hoodie/libavg