Electron v0.37.8 发布跨平台桌面应用开发工具

Electron v0.37.8 发布了，Electron跨平台桌面应用开发工具，基于 Web 技术。

主要改进如下：

Disable node integration in webview when it is disabled in host page. #5244
Make sure the userData directory is created during the ready event of app module. #5340
Throw error when autoUpdater.quitAndInstall() is called while there is no update. #5287
Add systemPreferences module. #5282
Add app.isDefaultProtocolClient(protocol) API. #5302
Fix occasional crash when doing GC. #5293
Fix app.makeSingleInstance(callback) wrongly returning true on first launch. #5311
Fix will-download event not emitted for HTML pages. #5315
Fix crash when navigating to a new location after downloading failed. #5315
Fix webContents.executeJavaScript not working after being called immediately after loadURL.#5319
Fix desktopCapturer.getSources not responding when there is subsequent calls with different arguments. #5320