lc.scm, pretty-format.scm: Fix a bug with displaying the output.

* ui/lc.scm (lazycat-exec): Fix a bug with displaying the output.
* ui/cli/pretty-format.scm (format-output-list): Likewise.
lazycatd.scm: Improve.  Add error handling.

* lazycat-daemon/lazycatd.scm (lazycat-exec): Improve.  Add error
  handling.