Scroll position is not preserved when file is modified outside the editor

To reproduce:

1. Open a file longer than the window, scroll down
2. Modify the file in another application (e.g. `touch` in Terminal)
3. Switch back to ST2

Expected result:

Scroll position and cursor on in the same place as before (as long as that line still exists in the file of course)

Actual result:

Window is scrolled to top, cursor is placed on beginning of the first line.

Build 2181, OS  X