Add missing dealloc
Trying to fix a Mavericks bug

Trying to fix a crash blindly: https://rink.hockeyapp.net/manage/apps/282/app_versions/384/crash_reasons/18140840

Looks similar to https://github.com/uranusjr/macdown/issues/100 which was fixed in https://github.com/uranusjr/macdown/commit/1ec349b4867e88dcc234a66abcc12bedb3e815dd

And drawing line numbers does something similar, so we may hit a weird 10.9.4 bug here too. Let's see how it goes.
Fix line number not being shown

This was introduced in the last commit, since it didn't handle all return cases
Export SMLGutterTextView to public headers