Libffi 3.2.1: headers not installed

[Hans Aberg]

The package libffi-3.2.1.tar.gz seems not to install the headers in /usr/local/include/ on OS X 10.10.2 (and there are none generated in the package directory libffi-3.2.1/include/). An earlier package from September installs them in /usr/include/, so possibly it has to do with the change of default install location (so if this is installed, one might not notice the issue).