Support for trackpad gestures on macOS, just like the web browser does.

[tevino]

First I'd like to say a big thanks for the great work, an awesome alternative to the official one.

It would be even better for a Mac user to use two finger to swipe left or right to go forward or backward, just like what the majority of applications on macOS does, like Firefox or Google Chrome.

For those who doesn't familiar with macOS, search for Swipe between pages here.