tcell build is commented out as it doesn't reliably respond to tmux
send-keys.

- Fix display of CJK wide characters
- Fix horizontal offset of header lines
- Add support for keys with ALT modifier, shift-tab, page-up and down
- Fix util.ExecCommand to properly parse command-line arguments
- Fix redraw on resize
- Implement Pause/Resume for execute action
- Remove runtime check of GOOS
- Change exit status to 2 when tcell failed to start
- TBD: Travis CI build for tcell renderer
    - Pending. tcell cannot reliably ingest keys from tmux send-keys

- Key bindings for bash, zsh, and fish
- Fuzzy completion for bash (file, dir, process)

With tmux-based test cases

They boot faster and since we don't use root we can use them.