Add swipe gestures to switch between open terminals

Created by: gscholt

Hi,

I often have multiple terminal open, and switching between them is cumbersome: edge swipe for menu, select other terminal, I have not found a key shortcut for it either.

Since swiping up/down scrolls the buffer, swiping left/right coud easily switch between the open terminals.

This featuree request relates to or can interact with mouse event generation of #35