- Electron version: v0.37.5
- Operating system: Any

It would be useful if we can open DevTools choosing all of it's available position: detached, docked right or docked bottom.

The new API could be something like this:
# webContents.openDevTools([options])

Opens the devtools.
- options Object (optional)
  - mode String - ['detached' | 'right' | 'bottom'] . opens DevTools in specified position. Defaults to last used mode.
  - detach Boolean - opens DevTools in a new window (deprecated, use mode: 'detached')

atom/browser/api/atom_api_web_contents.cc
net::HttpResponseHeaders* headers) {
    base::DictionaryValue response_headers;
    if (headers) {
      void* iter = nullptr;
      std::string key;
      std::string value;
      while (headers->EnumerateHeaderLines(&iter, &key, &value)) {
        key = base::ToLowerASCII(key);
        if (response_headers.HasKey(key)) {
          base::ListValue* values = nullptr;
          if (response_headers.GetList(key, &values))
            values->AppendString(value);
        } else {
          scoped_ptr<base::ListValue> values(new base::ListValue());
          values->AppendString(value);
          response_headers.Set(key, std::move(values));
        }
      }
    }
    return ConvertToV8(isolate, response_headers);
  }
};
template<>
struct Converter<content::SavePageType> {
  static bool FromV8(v8::Isolate* isolate, v8::Local<v8::Value> val,