Determine how to allocate external C structures correctly

[robertzk]

http://book.realworldhaskell.org/read/interfacing-with-c-the-ffi.html

Then we can add the correct types around the C functions.

[robertzk]

@michaelochurch says https://hackage.haskell.org/package/carray-0.1.5.2/docs/Data-Array-CArray.html