Lemmih/hsSDL2 — pull request #40 by albertfong (2014-03-25 10:16:08+00:00)
Title: Add DisplayMode related functions

Might want to double check my changes, since I'm only just ramping up on Haskell / FFI.

Adds the following:
```
getClosestDisplayMode
getCurrentDisplayMode
getDesktopDisplayMode
getDisplayMode
setWindowDisplayMode
getWindowDisplayMode
```