porting to OS X Snow Leopard x86-64
switching to stdlib.h which works on both apple and linux
Merge pull request #11 from stevej/stevej/mac_os_x

porting to OS X Snow Leopard x86-64
some legal stuff required by my employer
Updating for llvm 3.1 and Ocaml 4.0

Part of the update is trivial, just changing the version numbers in configure script.

Adapting to the type handling change in llv3 3.0 was a bit more involved, mostly because I needed to figure out what is happennig. But the change is rather simple 
and straigthforward.

The obsoleted command options for llvm opt are just commented out, because I'm
not sure what their equivalents are.
The '%' (mod) was missing in check_binop. So the following did not compile

module TestMod = struct

    val main : unit -> unit
    let main () = 
        Print.int (7 % 2);
        Print.newline ()
end
Merge pull request #12 from vrotaru/master

Update for llvm 3.1 (ocaml 4.0)