Add Support for Older Browsers

[rileymd88]

It would be nice if there were some options on how to define the webpack that would allow for better browser compatibility/use of polyfills etc. I can of course do this manually be changing the define-webpack.js file, however it would be nice if a few options could be chosen when creating a new extension.

[jbellizzi]

Thanks for the comment @rileymd88. I'm currently working on a newer version of qExt and keeping this in mind as a new feature