add intel/2014b toolchain definition, which includes GCC/4.8.3 as a dependency

depends on https://github.com/hpcugent/easybuild-easyblocks/pull/429 to ensure that FFTW wrappers libraries for Intel MKL are installed correctly

@gjbex, @hajgato, @JensTimmerman: please review?
what we *really* need is a constant provided by the framework that points to the home directory, rather than importing `os` in an easyconfig file...

So let's fix it that way rather than switching to `expanduser` in here. Anyone up for that? @JensTimmerman?