It doesn't look very good for "native" apps to overscroll when scrolling. Would be nice to have a BrowserWindow option to disable overscroll

![untitled12](https://cloud.githubusercontent.com/assets/170270/15033357/fc36e32e-1293-11e6-8cdc-6c17b0f504dd.gif)
## 
- Electron version: 0.37.8
- Operating system: OS X 10.11.4

atom/common/options_switches.h
#ifndef ATOM_COMMON_OPTIONS_SWITCHES_H_
#define ATOM_COMMON_OPTIONS_SWITCHES_H_
namespace atom {
namespace options {
extern const char kTitle[];
extern const char kIcon[];
extern const char kFrame[];
extern const char kShow[];
extern const char kCenter[];
extern const char kX[];
extern const char kY[];
extern const char kWidth[];
extern const char kHeight[];
extern const char kMinWidth[];