Introduce a collection of wrappers for C++ stdlib functions
Introduce a collection of wrappers for C++ stdlib functions

Summary:
Cython provides wrappers of many common classes and functions in the C++
standard library. However it doesn't include everything. This diff wraps a
couple functions used in manipulating containers, including find and count,
along with the iterator_traits type used to wrap them.

Reviewed By: yfeldblum

Differential Revision: D4212006

fbshipit-source-id: e07e53ccaa45e359d682b794c93f9893bb308f7c

SergeyMakarenko/fbthrift,SergeyMakarenko/fbthrift,SergeyMakarenko/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,facebook/fbthrift,getyourguide/fbthrift,facebook/fbthrift,getyourguide/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,getyourguide/fbthrift,facebook/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,SergeyMakarenko/fbthrift,SergeyMakarenko/fbthrift,facebook/fbthrift,getyourguide/fbthrift,facebook/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,SergeyMakarenko/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,getyourguide/fbthrift,facebook/fbthrift,getyourguide/fbthrift