Modify library to build under CentOS 6.6, which has the following libs:
* boost 1.41
* cmake 2.8.12
* libmad 0.15 (available from rpmforge)
* libdnsfile 1.0.20
* gd 2.0.35
* g++ 4.4.7

cmake must be called with -DBoost_NO_BOOST_CMAKE=ON because of a small
issue in the boost 1.41 cmake files.

WARNING: I'm not a C++ developer, just adapted the code, which works
for me and passes all tests. Sharing on github only for convenience
and because is open source :)