Building Pillow from source with TIFF support fails in Windows

[ignaciordc]

I downloaded the sources from GitHub,
modified Setup.py to point to my additional libraries
run the command "python setup.py build", in windows XP

=>the build process fails because there is a file, "unistd.h" that is required
by "Tiffdecode.h" that does not exist in XP.
Creating a more-or-less valid one, the package is able to continue.

Also, running the command "python setup.py clean", deletes all the files under the build directory, but not the directory itself. Running "build" again fails, for it assumes everything is in place. I think, though, this is not a Pillow issue.

Using distutils I verified that I was using MSC ver 9.0

[aclark4life]

Can you send a pull request?