esh-autosuggest only provides history completion, which isn't very
useful, especially when we already have history search (via ivy/helm)
available on 'C-s' in eshell.
The active company-backends have been rearranged so that company-capf is
the main completer, but will fall back to company-files (since capf
doesn't complete files, only directories and commands).
I wish there were something more robust, however. Perhaps a way to
integrate pcomplete into company?
