Quagga routing suite

Here's a formula for the current stable version of Quagga.

The long ``./configure`` enables all the daemons/protocols and especially the remote admin/CLI tool ``vtysh``, which is used to remotely administer these daemons and general routing on other routers (as well as maybe locally).

Thanks to mistym on IRC
Also, can you report this to the upstream developers of this project and add a link to the upstream issue submission in a comment in the formula file. Thanks!