This way, tests are shorter, and i3test’s invocation of launch_with_config parallelizes work better, using dont_block => 1.
Not calling exit_gracefully causes some other test to fail during a complete_run sometimes.
cmd_resize does not implement a method to resize dock clients. A command like `[instance=".*"] resize grow width 160 px or 16 ppt` when a dock client matched would crash i3. fixes #1201