Add support for ForkLift 2 to the ForkLift plugin

The ForkLift plugin now supports ForkLift 2 as well as ForkLift 1.
If ForkLift is not running it also waits for it to be running before
trying to switch to the specified directory
Merge pull request #2132 from jkaving/forklift2

Add support for ForkLift 2 to the ForkLift plugin