Haskell FreeType binding, plus ZBmp

Copperbox revision 421.

More work on the FreeType binding, plus start of a new library for working with *.bmp bitmap files. I want to be able to test the rendering form FreeType - currently it can write an Ascii rendition of a single character but I really need to be able to write bitmaps.

The available Haskell libraries for graphics (GD, GraphicsMagick, ...) seem to be bindings over substantial C libraries. This is more than I need, so I've started ZBmp to read and write *.bmp files. I want it to be almost as simple as possible[1] and have no dependencies outside the GHC base libraries.

[1] Currently it's too simple as it uses [[pixel]] - list of list of pixels - I'll make it use arrays in due course.