runCommand -package:wai-app-static -package:libmpd -package:pandoc-plot -package:beam-migrate -package:shake -package:quickcheck-state-machine is:exact -package:options -package:process -package:cabal-install -package:hledger -package:github-release -package:mongoDB -package:graphviz -package:io-streams
Given a list of command/action pairs, prompt the user to choose a
command using dmenu and return the corresponding action.