fixes: selecting error, drawing regions, added selected region

Regions now does not span several lines. Also when a few regions had the same begin and end, there was a bug with selecting it from quick panel. This was because when adding regions, i.e [(1, 2), (1, 2), (2, 3)], sublime returned only unique ones [(1, 2), (2, 3)] with view.get_regions('jshint_selected'). This caused method on_chosen to point to invalid or non-existing region.

I also added a higlight for selected region.
Merge pull request #50 from borysf/master

fixes: selecting error, drawing regions, added selected region