Add git-gutter-fr:line-to-pos

Ideally git-gutter-fringe would start working the same way git-gutter
has been changed to figure out the changes, but this at least makes it
work rather than calling a non-existing function.
Merge pull request #12 from tanzoniteblack/line-to-pos

Add git-gutter-fr:line-to-pos
Bump up version and update Changes

- update git-gutter version