blitz include error on multilib installations

Created by: ozancaglayan

Fedora installs architecture dependent blitz/gnu/bzconfig.h header into /usr/lib64/blitz/include. This path should be included when building the project. This is already indicated in the pkgconfig file of blitz package in Cflags:

Name: blitz
Description: blitz Library
Version: 0.9
Requires: 
Libs: -L${libdir} -lblitz
Cflags: -I${includedir} -I${libdir}/blitz/include

but CMake is not aware of that. I've adjusted src/blitz.cmake and added the following line to fix this:

include_directories(/usr/lib64/blitz/include)

This can probably be done in a more elegant way but I don't know how.

Thanks.