I'm interested to install GNU m4 1.4 or later into `/usr/bin/`, I installed Homebrew, like this, `ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)"`, to be able to insall `bfgminer`, but when I got to `brew install bfgminer`–more or less following [these instructions](http://blog.nwoolls.com/2013/04/24/bitcoin-mining-on-mac-os-x-cgminer-bfgminer/)–I get told that `need GNU m4 1.4 or later: /usr/bin/m4`. 

Can anyone tell me how I install GNU m4 1.4 or later on OSX 10.8.5?