fix is app installed and tests

modify/show show error on empty file

do not print errors if checking whether app is installed and it isnt

do not print errors if checking whether app is installed and it isnt

use same engine as tests run with for 'no suggestions in non-TTY mode'

let modify create file for auto/set/add mode and show all modify opti…

…ons in help

tty mocking

improved command suggestions for unknown commands

Command hints (#25)

* Add Levenshtein distance function and command suggestion feature to CLI
* tests and improvements

update to lua 5.5