yi-editor/yi — pull request #23 by ethercrow (2012-06-14 19:20:06+00:00)
Title: Prevent vertical cursor motion in vim normal mode from forgetting column

Consider text like this:
```
1234567
abcd
ijklmnopqrt
```

where cursor stands at '7'

Pressing ```2j``` brings cursor to 'o', which is expected.
Pressing ```jj```, which should be equivalent to ```2j```, brings cursor to 'l'.

Proposed patch fixes that.

It also exposes getPrefCol, which can be used in user-defined modeline, for example. That certainly helped while investigating the issue.