Merge pull request #2 from iurifq/master

Fix for files opened not in the the current dir.
improve check for sign on current line
Merge branch 'master' of https://github.com/gilligan/textobj-gitgutter

* 'master' of https://github.com/gilligan/textobj-gitgutter:
  Fix for files opened not in the the current dir.
fix translation problem

the :sign output translation breaks s:line_has_sign
Fix line_has_sign() again
Add missing file parameter of GitGutter function.