Also look for ffi.h under /usr/local/include

Created originally on Bitbucket by bencord0 (Benjamin Cordero)

Was already merged in Bitbucket before import, marked as merged by the import user

The ffh.h header is stored as /usr/local/include/ffi.h on FreeBSD.

Adding this to the search path allows "pip install cffi" to work.

This can be reproduced on FreeBSD 10.1 with:

$ sudo pkg install py27-virtualenv $ virtualenv venv $ ./venv/bin/pip install cffi