I tried a clean install of raspbian wheezy,
and now it does find and install g++4.8. (with the above code added to install_dependencies)
However it will leave 4.6 as the default. so either call g++-4.8 manually in the makefile
or I guess use something like
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 20
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 50
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.6 20
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 50
to prefer version 4.8
