Start new tabs with a different shell

[aedelsten]

Add ability to right-click on a terminal tab and select different shells to run (idea totally stolen from the new MS Windows Console). Could list the shells in the config file, use the first entry as the default but allow user to choose and then launch.

See: https://youtu.be/8gw0rXPMMPE?t=13

Perceived idea awesomeness

• Would be super cool.

Perceived idea difficulty

• Shouldn't be too hard to make.